Academic literature on the topic 'Protease inhibitors'
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Journal articles on the topic "Protease inhibitors"
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Paulin, John P., and Francisco C. Franco. "Modified bis‐tetrahydrofuran inhibitors toward improved binding to HIV‐1 proteases." Vietnam Journal of Chemistry 59, no. 5 (2021): 563–79. http://dx.doi.org/10.1002/vjch.202000179.
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AbstractHIV treatment includes inhibiting HIV‐1 protease which is responsible for viral maturation. However, HIV‐1 protease responds to drug treatment by mutation making the protease‐resistant to inhibitors. In this study, binding interactions between bis‐tetrahydrofuran‐derived (bis‐THF) inhibitors and HIV‐1 protease were described by molecular docking. We characterized the binding energies and all the amino acids present during the binding of the bis‐THF derivatives to the wild type HIV‐1 protease and several mutant HIV‐1 proteases. We found that the modifications to the structure of darunavir helped improve its binding to the wild‐type protease. Also, these structures were found to interact with the mutant HIV‐1 proteases better than darunavir. Results showed that compound 4 had the highest binding energy to the wild‐type HIV‐1 protease and the V654/84 mutant, while compound 5 was found to interact greatly with cyclic urea‐based inhibitor‐resistant proteases and the multi‐protease inhibitor‐resistant HIV‐1 protease. The results may help explain how structural modifications to bis‐tetrahydrofuran inhibitors affect their response to wild‐type and resistant HIV‐1 proteases. Furthermore, this study is the first demonstration of the differences in the amino acids interacting with protease inhibitors for wild‐type and mutated HIV‐1 proteases and may help in the design of bis‐THF derivatives as HIV‐1 protease inhibitors.
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Mihelič, Marko, and Dušan Turk. "Two decades of thyroglobulin type-1 domain research." Biological Chemistry 388, no. 11 (2007): 1123–30. http://dx.doi.org/10.1515/bc.2007.155.
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Abstract Thyroglobulin type-1 repeats are primarily found in thyroglobulin and several other functionally unrelated proteins. Because a few of them exhibit inhibitory activity against cysteine proteases they were named thyropins (thyroglobulin type-1 domain protease inhibitors). In contrast to cystatins, the best-characterized group of papain-like protease inhibitors, they exhibit greater selectivity in their interactions with target proteases. Interestingly, a few members inhibit aspartic protease cathepsin D and metalloproteases. In contrast to the inhibitory fragment of the major histocompatibility complex class II-associated p41 form of invariant chain, whose structural integrity appears mandatory for its inhibitory properties, short polypeptides derived from insulin-like growth factor-binding proteins exhibit the same activity as the structure of the whole fragment. Taken together, the results indicate that the thyroglobulin type-1 repeat is a structural motif occasionally employed as an inhibitor of proteases.
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Wang, Q. May, Robert B. Johnson, Louis N. Jungheim, Jeffrey D. Cohen, and Elcira C. Villarreal. "Dual Inhibition of Human Rhinovirus 2A and 3C Proteases by Homophthalimides." Antimicrobial Agents and Chemotherapy 42, no. 4 (1998): 916–20. http://dx.doi.org/10.1128/aac.42.4.916.
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ABSTRACT The 2A and 3C proteases encoded by human rhinoviruses (HRVs) are attractive targets for antiviral drug development due to their important roles in viral replication. Homophthalimides were originally identified as inhibitors of rhinovirus 3C protease through our screening effort. Previous studies have indicated that the antiviral activity of certain homophthalimides exceeded their in vitro inhibitory activity against the viral 3C protease, suggesting that an additional mechanism might be involved. Reported here is the identification of homophthalimides as potent inhibitors for another rhinovirus protease, designated 2A. Several homophthalimides exhibit time-dependent inhibition of the 2A protease in the low-micromolar range, and enzyme-inhibitor complexes were identified by mass spectrometry. Compound LY343814, one of the most potent inhibitors against HRV14 2A protease, had an antiviral 50% inhibitory concentration of 4.2 μM in the cell-based assay. Our data reveal that homophthalimides are not only 3C but also 2A protease inhibitors in vitro, implying that the antiviral activity associated with these compounds might result from inactivation of both 2A and 3C proteases in vivo. Since the processing of the viral polyprotein is hierarchical, dual inhibition of the two enzymes may result in cooperative inhibition of viral replication. On the basis of the current understanding of their enzyme inhibitory mechanism, homophthalimides, as a group of novel nonpeptidic antirhinovirus agents, merit further structure-action relationship studies.
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Chen, Xingchen, Darren Leahy, Jessica Van Haeften, et al. "A Versatile and Robust Serine Protease Inhibitor Scaffold from Actinia tenebrosa." Marine Drugs 17, no. 12 (2019): 701. http://dx.doi.org/10.3390/md17120701.
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Serine proteases play pivotal roles in normal physiology and a spectrum of patho-physiological processes. Accordingly, there is considerable interest in the discovery and design of potent serine protease inhibitors for therapeutic applications. This led to concerted efforts to discover versatile and robust molecular scaffolds for inhibitor design. This investigation is a bioprospecting study that aims to isolate and identify protease inhibitors from the cnidarian Actinia tenebrosa. The study isolated two Kunitz-type protease inhibitors with very similar sequences but quite divergent inhibitory potencies when assayed against bovine trypsin, chymostrypsin, and a selection of human sequence-related peptidases. Homology modeling and molecular dynamics simulations of these inhibitors in complex with their targets were carried out and, collectively, these methodologies enabled the definition of a versatile scaffold for inhibitor design. Thermal denaturation studies showed that the inhibitors were remarkably robust. To gain a fine-grained map of the residues responsible for this stability, we conducted in silico alanine scanning and quantified individual residue contributions to the inhibitor’s stability. Sequences of these inhibitors were then used to search for Kunitz homologs in an A. tenebrosa transcriptome library, resulting in the discovery of a further 14 related sequences. Consensus analysis of these variants identified a rich molecular diversity of Kunitz domains and expanded the palette of potential residue substitutions for rational inhibitor design using this domain.
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Cheng, Ting-Jen, Ashraf Brik, Chi-Huey Wong, and Chen-Chen Kan. "Model System for High-Throughput Screening of Novel Human Immunodeficiency Virus Protease Inhibitors in Escherichia coli." Antimicrobial Agents and Chemotherapy 48, no. 7 (2004): 2437–47. http://dx.doi.org/10.1128/aac.48.7.2437-2447.2004.
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ABSTRACT Novel human immunodeficiency virus (HIV) protease inhibitors are urgently needed for combating the drug-resistance problem in the fight against AIDS. To facilitate lead discovery of HIV protease inhibitors, we have developed a safe, convenient, and cost-effective Escherichia coli-based assay system. This E. coli-based system involves coexpression of an engineered β-galactosidase as an HIV protease substrate and the HIV protease precursor comprising the transframe region and the protease domain. Autoprocessing of the HIV protease precursor releases the mature HIV protease. Subsequently, the HIV protease cleaves β-galactosidase, resulting in a loss of the β-galactosidase activity, which can be detected in high-throughput screens. Using Food and Drug Administration-approved HIV protease inhibitors, this E. coli-based system is validated as a surrogate screening system for identifying inhibitors that not only possess inhibitory activity against HIV protease but also have solubility and permeability for in vivo activity. The usefulness of the E. coli-based system was demonstrated with the identification of a novel HIV protease inhibitor from a library of compounds that were prepared by an amide-forming reaction with transition-state analog cores. A novel inhibitor with a sulfonamide core of amprenavir, E2, has shown good correlation with the in vitro enzymatic assay and in vivo E. coli-based system. This system can also be used to generate drug resistance profiles that could be used to suggest therapeutic uses of HIV protease inhibitors to treat the drug-resistant HIV strains. This simple yet efficient E. coli system not only represents a screening platform for high-throughput identification of leads targeting the HIV proteases but also can be adapted to all other classes of proteases.
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Mallia-Milanes, Brendan, Antoine Dufour, Christopher Philp, et al. "TAILS proteomics reveals dynamic changes in airway proteolysis controlling protease activity and innate immunity during COPD exacerbations." American Journal of Physiology-Lung Cellular and Molecular Physiology 315, no. 6 (2018): L1003—L1014. http://dx.doi.org/10.1152/ajplung.00175.2018.
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Dysregulated protease activity is thought to cause parenchymal and airway damage in chronic obstructive pulmonary disease (COPD). Multiple proteases have been implicated in COPD, and identifying their substrates may reveal new disease mechanisms and treatments. However, as proteases interact with many substrates that may be protease inhibitors or proteases themselves, these webs of protease interactions make the wider consequences of therapeutically targeting proteases difficult to predict. We therefore used a systems approach to determine protease substrates and protease activity in COPD airways. Protease substrates were determined by proteomics using the terminal amine isotopic labeling of substrates (TAILS) methodology in paired sputum samples during stable COPD and exacerbations. Protease activity and specific protein degradation in airway samples were assessed using Western blotting, substrate assays, and ex vivo cleavage assays. Two hundred ninety-nine proteins were identified in human COPD sputum, 125 of which were proteolytically processed, including proteases, protease inhibitors, mucins, defensins, and complement and other innate immune proteins. During exacerbations, airway neutrophils and neutrophil proteases increased and more proteins were cleaved, particularly at multiple sites, consistent with degradation and inactivation. During exacerbations, different substrates were processed, including protease inhibitors, mucins, and complement proteins. Exacerbations were associated with increasing airway elastase activity and increased processing of specific elastase substrates, including secretory leukocyte protease inhibitor. Proteolysis regulates multiple processes including elastase activity and innate immune proteins in COPD airways and differs during stable disease and exacerbations. The complexity of protease, inhibitor, and substrate networks makes the effect of protease inhibitors hard to predict which should be used cautiously.
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Tušar, Livija, Aleksandra Usenik, Boris Turk, and Dušan Turk. "Mechanisms Applied by Protein Inhibitors to Inhibit Cysteine Proteases." International Journal of Molecular Sciences 22, no. 3 (2021): 997. http://dx.doi.org/10.3390/ijms22030997.
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Protein inhibitors of proteases are an important tool of nature to regulate and control proteolysis in living organisms under physiological and pathological conditions. In this review, we analyzed the mechanisms of inhibition of cysteine proteases on the basis of structural information and compiled kinetic data. The gathered structural data indicate that the protein fold is not a major obstacle for the evolution of a protease inhibitor. It appears that nature can convert almost any starting fold into an inhibitor of a protease. In addition, there appears to be no general rule governing the inhibitory mechanism. The structural data make it clear that the “lock and key” mechanism is a historical concept with limited validity. However, the analysis suggests that the shape of the active site cleft of proteases imposes some restraints. When the S1 binding site is shaped as a pocket buried in the structure of protease, inhibitors can apply substrate-like binding mechanisms. In contrast, when the S1 binding site is in part exposed to solvent, the substrate-like inhibition cannot be employed. It appears that all proteases, with the exception of papain-like proteases, belong to the first group of proteases. Finally, we show a number of examples and provide hints on how to engineer protein inhibitors.
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Josephrajkumar, A., R. Chakrabarty, and G. Thomas. "Midgut proteases of the cardamom shoot and capsule borerConogethes punctiferalis(Lepidoptera: Pyralidae) and their interaction with aprotinin." Bulletin of Entomological Research 96, no. 1 (2006): 91–98. http://dx.doi.org/10.1079/ber2005403.
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AbstractProtease inhibitors cause mortality in a range of insects, and transgenic plants expressing protease inhibitors have been protected against pest attack, particularly internal feeders that are not amenable to control by conventional means. A study of luminal proteases inConogethes punctiferalisGuenée was performed to identify potential targets for proteinaceous biopesticides, such as protease inhibitors. The midgut protease profile of the gut lumen fromC. punctiferaliswas studied to determine the conditions for optimal protein hydrolysis. Optimum conditions for peptidase activity were found to be in 50 mm Tris-HCl, pH 10 containing 20 mm CaCl2; incubation for 30 min at 40°C. Four synthetic substrates, i.e. benzoyl-arg-p-nitroanilide, benzoyl-tyr-p-nitroanilide, succinyl-ala-ala-pro-leu-p-nitroanilide (SAAPLpNA) and leu-p-nitroanilide were hydrolysed byC. punctiferalisgut proteases in Tris-HCl buffer pH 10. Trypsin and elastase-like chymotrypsin were the prominent digestive proteases, and age-related modulation of midgut proteases existed for trypsin, chymotrypsin, elastase-like chymotrypsin and leucine aminopeptidase. Serine protease inhibitors such as aprotinin, soybean trypsin inhibitor and phenylmethanesulfonyl fluoride inhibited peptidase activity. Some metal ions such as Ca2+, Mg2+, Pb2+and Co2+enhanced BApNA-ase activity whereas others like Mn2+, Zn2+, Cu2+, Fe2+and Hg2+were inhibitory at 6 mm concentration. Trypsin and elastase-like chymotrypsin were significantly inhibited by 94% and 29%, respectively, by aprotinin (150 nm) underin vitroconditions. A possible incorporation of protease inhibitors into transgenic plants is discussed.
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Brüning, Mareke, Martina Lummer, Caterina Bentele, Marcel M. W. Smolenaars, Kees W. Rodenburg, and Hermann Ragg. "The Spn4 gene from Drosophila melanogaster is a multipurpose defence tool directed against proteases from three different peptidase families." Biochemical Journal 401, no. 1 (2006): 325–31. http://dx.doi.org/10.1042/bj20060648.
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By alternative use of four RSL (reactive site loop) coding exon cassettes, the serpin (serine protease inhibitor) gene Spn4 from Drosophila melanogaster was proposed to enable the synthesis of multiple protease inhibitor isoforms, one of which has been shown to be a potent inhibitor of human furin. Here, we have investigated the inhibitory spectrum of all Spn4 RSL variants. The analyses indicate that the Spn4 gene encodes inhibitors that may inhibit serine proteases of the subtilase family (S8), the chymotrypsin family (S1), and the papain-like cysteine protease family (C1), most of them at high rates. Thus a cohort of different protease inhibitors is generated simply by grafting enzyme-adapted RSL sequences on to a single serpin scaffold, even though the target proteases contain different types and/or a varying order of catalytic residues and are descendents of different phylogenetic lineages. Since all of the Spn4 RSL isoforms are produced as intracellular residents and additionally as variants destined for export or associated with the secretory pathway, the Spn4 gene represents a versatile defence tool kit that may provide multiple antiproteolytic functions.
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Avanzo, Petra, Jerica Sabotič, Sabina Anžlovar, et al. "Trypsin-specific inhibitors from the basidiomycete Clitocybe nebularis with regulatory and defensive functions." Microbiology 155, no. 12 (2009): 3971–81. http://dx.doi.org/10.1099/mic.0.032805-0.
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We have isolated serine protease inhibitors from the basidiomycete Clitocybe nebularis, CnSPIs, using trypsin affinity chromatography. Full-length gene and cDNA sequences were determined for one of them, named cnispin, and the recombinant protein was expressed in Escherichia coli at high yield. The primary structure and biochemical properties of cnispin are very similar to those of the Lentinus edodes serine protease inhibitor, until now the only member of the I66 family of protease inhibitors in the MEROPS classification. Cnispin is highly specific towards trypsin, with K i in the nanomolar range. It also exhibited weaker inhibition of chymotrypsin and very weak inhibition of subtilisin and kallikrein; other proteases were not inhibited. Inhibitory activity against endogenous proteases from C. nebularis revealed a possible regulatory role for CnSPIs in the endogenous proteolytic system. Another possible biological function in defence against predatory insects was indicated by the deleterious effect of CnSPIs on the development of larvae of Drosophila melanogaster. These findings, together with the biochemical and genetic characterization of cnispin, suggest a dual physiological role for this serine protease inhibitor of the I66 MEROPS family.
Dissertations / Theses on the topic "Protease inhibitors"
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De, Veer Simon J. "Development of novel protease inhibitors for epidermal kallikrein proteases." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/114508/1/Simon_de%20Veer_Thesis.pdf.
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Preserving the integrity of the skin's outermost layer (the epidermis) is vital for humans to thrive in hostile surroundings. Covering the entire body, the epidermis forms a thin but impenetrable cellular cordon that repels external assaults and blocks the escape of water and electrolytes from within. This structure exists in a perpetual state of repair and regeneration where the production of new cellular subunits (keratinocytes) at the base of the epidermis is offset by the gradual release of terminally differentiated corneocytes from the surface. It is increasingly clear that proteinases (hereafter termed proteases) are essential for assembling and maintaining the epidermal barrier. More than thirty proteases are expressed by keratinocytes or immune cells that infiltrate the skin, and the activity of each must be maintained within narrow limits and confined to the correct time and place. Accordingly, dysregulated proteolytic activity is a common factor in a multitude of skin disorders that range in severity from relatively mild to life-threatening.
Serine proteases from the kallikrein-related peptidase (KLK) family are widely recognised as key modulators of epidermal barrier function. For several decades, KLK proteases have been regarded as major contributors to the natural shedding of corneocytes from the skin's surface by degrading (corneo)desmosomes in the stratum corneum. Additionally, controlled KLK proteolytic activity influences the step-wise processing of key molecules involved in hydration and acidification (pro-filaggrin), and anti-microbial defence (cathelicidins).
Further, KLK proteases have prominent roles in the response to barrier disruption that involve stimulating inflammation and alerting the immune system. Thus, failure to properly control KLK proteolytic activity represents a significant threat to epidermal barrier function, as seen in a spectrum of skin disorders, including Netherton syndrome and atopic dermatitis.
The focus of this study was to develop novel inhibitors for three KLK proteases with the strongest links to epidermal (patho)physiology (KLK5, KLK7 and KLK14) by engineering the naturally occurring cyclic peptide, sunflower trypsin inhibitor-1 (SFTI-1). Initially, each target protease was screened against a dedicated library of individually synthesised peptide substrates (sparse matrix library) to identify sequence combinations that bound to the active site with high affinity. This approach yielded a series of efficient tetrapeptide substrates for each protease that outperformed existing substrates from conventional screening methods, such as positional scanning and phage display. Strikingly, the optimal substrates for KLK5, KLK7 and KLK14 each displayed a unique physicochemical signature, indicating that the active site of each protease was configured to recognise distinct cleavage motifs. This phenomenon was explored in more detail by analysing structures of diverse serine proteases from the S1A (chymo)trypsin fold, which identified several points of high sequence variation in the active site cleft that likely contribute to divergent cleavage site specificities.
Subsequently, favoured cleavage sequences for KLK5, KLK7 and KLK14 were substituted into the contact β-strand of SFTI-1 to generate inhibitor variants with improved affinity and selectivity. Whereas most inhibitor design strategies based on Laskowski inhibitors (including SFTI-1) focus mainly on optimising the interaction between protease and inhibitor, this study paired binding loop modifications with a second step that aimed to refine the intramolecular hydrogen bond network, as shown recently for engineered SFTI variants targeting KLK4. Like the previous study, improving the tendency for an inhibitor to form intramolecular hydrogen bonds generally led to improvements in inhibitory activity.
However, it was also evident that certain hydrogen bonds were detrimental, revealing that the quantity of hydrogen bonds should not be the only criteria during this screening process.
Additionally, the iterative optimisation of inhibitors for KLK5 highlighted the need to consider both sides of the reactive site when engineering Laskowski inhibitors as generating a selective KLK5 variant was dependent on substituting the P2′ residue. Using this design process, it was possible to successfully re-direct the inhibitory activity of SFTI-1 to three separate protease targets that showed varying affinity for the wild-type inhibitor.
To delve further into the Laskowski mechanism, SFTI-1 was used as a model system to explore the molecular basis for Laskowski inhibitor potency and specificity. Here, inhibitor association and dissociation kinetics were characterised for a series of variants with different binding sequences and hydrogen bond tendencies. These analyses revealed that the primary determinant for rapid association was the pre-organised conformation of the inhibitor binding loop rather than its sequence, whereas coordinated inter- and intramolecular interactions promoted efficient religation and slow dissociation. As the conformation of the binding loop is conserved, inhibitor selectivity dictated by the binding sequence was found to arise from modulating the off-rate. Performing additional analyses on eight fold-divergent inhibitor families revealed that these concepts were generally applicable to Laskowski inhibitors, providing broad new insights on protease inhibitor function and design. These findings were subsequently applied to engineer an additional series of potent inhibitors with broad-range activity.
Finally, the substrates and inhibitors developed for KLK5, KLK7 and KLK14 were used in biological assays to investigate the activity and significance of each target protease in healthy and diseased skin. KLK peptide substrates were applied to profile KLK hyperactivity in skin extracts from transgenic KLK5 mice and Spink5-/- mice. Additionally, KLK inhibitors were used to sequentially block different KLKs in gel-based and in situ zymography experiments. Selective and broad-range inhibitors were also evaluated in ex vivo desquamation assays to examine the relative importance of KLK5, KLK7 and KLK14 during corneocyte shedding, which revealed a major role for KLK7. Collectively, these findings shed light on the individual contributions of KLK proteases to maintaining the epidermal barrier and identify a series of therapeutic leads for further development as novel treatments for skin disorders associated with dysregulated KLK proteolytic activity.
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Tiew, Kok-Chuan. "Dengue virus protease inhibitors." Thesis, Wichita State University, 2011. http://hdl.handle.net/10057/6117.
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Dengue virus (DENV) is a major health threat that affects 2.5 billion people, or 40% of the world’s population. However, there are no approved antiviral drugs or vaccines to treat Dengue infection. This thesis describes the design, synthesis and discovery of a new class of inhibitors of DENV NS3 protease. Structure-activity relationship studies have been carried out in order to delineate the structural elements responsible for the activity of this series of compounds. A lead compound suitable for further development has been identified.<br>Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry.
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Hamill, J. A. "Involvement of proteases and protease inhibitors in potato late blight." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426731.
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James, Karen Amanda Ellis. "Design, synthesis, and evaluation of novel cysteine protease inhibitors." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/30283.
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Mendieta, Martínez Laura. "Protease inhibitors as therapeutic agents." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/279388.
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Proteases are involved in a high number of diseases, and thus, are relevant targets. For that reason our main goal was the discovery of protease inhibitors as therapeutic agents.
We focused our study in four proteases: dipeptidyl peptidase IV (diabetes mellitus type 2), prolyl oligopeptidase (cognitive disorders) and cathepsins L and B (cancer).For the discovery of inhibitors, three strategies were selected: medicinal plant screening, high throughput screening and the characterization of a combinatorial chemistry library.
Once accomplished the DPP IV recombinant expression optimization, the protein was studied by means of nuclear magnetic resonance (NMR) in order to obtain information of its dynamism. Since DPP IV is a large protein, a strategy combining selective labeling and the use of TROSY-HSQC experiments was used. From the 14 methionine residues of the protease, 11 of them were detected in the NMR spectra.
Then, a study of the inhibitor effect on the NMR spectra of DPP IV was done. Interestingly, the corresponding spectra of DPP IV / inactivator afforded an extra signal.
We believe that it is a consequence of a small structural change that the protease suffers after inhibition.
Afterwards, we planned to find DPP IV from botanical sources.
First, we selected plants that were already reported to have antidiabetic action.
Common antidiabetic plants were chosen, as well as Brazilian plants and others from the Traditional Chinese Medicine. Besides, a library of Mediterranean plants was also selected.
After, extraction and testing of DPP IV inhibitory activity was done.
From our tailored collection, the plant AP-3 was selected for further analysis. After fractionation and purification, two molecules were found to be DPP IV inhibitors. Kinetic experiments of the best one, AP-3-a, demonstrated that it was inhibiting DPP IV in a parabolic manner.
Then, AP-3-a inhibition of DPP IV was analysed by NMR. The extra signal that was observed with competitive inhibitors was not present.
We hypothesized that the lack of appearance of this signal is a result of the parabolic inhibition of AP-3-a.
Then, we planned the identification of POP inhibitors by HTS.
Our strategy was based in the use of libraries containing non-toxic compounds and lead-like properties. The assay we selected was FP, which allowed the identification of protein binders by competition with a fluorophore-labelled probe.
First, the peptide probes were validated as useful probes for the FP assay. Then, the HTS was carried out. Over the 4,500 tested compounds, 73 hits were found to be POP binders. Later, 37 hits were selected by means of clustering, docking data and FP results in order to be validated as POP inhibitors. The subset of molecules was evaluated by enzymatic assays. Six compounds presenting the highest POP inhibition ration were selected for further study. Finally, two POP inhibitors have been described. HTS-43 is a competitive POP inhibitor and HTS-75 displays a parabolic behaviour.
It was the first time that parabolic inhibition is reported for POP. We believe that the existence of a non-competitive site would help in the understanding of the relationship between POP and mental diseases.
Finally, a novel peptidyl aryl vinyl sulfone library was tested for its inhibitory activity against cathepsins L and B.
Among all the 20 molecules of the library, a potent covalent irreversible cathepsin L inhibitor has been found, PAVS-20. The progress-curve of the pre-incubation time representation allowed the calculation of its inhibition constants.
Furthermore, evaluation of subsite preferences was done by docking analysis. This allowed understanding the experimental differences in inhibition constants obtained for similar compounds.
Since cathepsins L and B are targets for cancer, molecules of the PAVS library are promising candidates for the development of new anticancer drugs.<br>Las proteasas están involucradas en un alto número de enfermedades y por lo tanto, son dianas terapéuticas relevantes. Por este motivo, nuestra principal meta era el descubrimiento de inhibidores de proteasas cómo agentes terapéuticos. Para ello nuestro estudio en cuatro proteasas: la dipeptidil peptidasa IV, la prolil oligopeptidasa y las catepsinas L y B.
Para la búsqueda de inhibidores, se seleccionaron tres estrategias: cribado de plantas medicinales, cribado de alto rendimiento y caracterización de una biblioteca proveniente de la química combinatoria.
Una vez se llevó a cabo la expresión recombinante de la DPPIV, la proteína se estudió mediante resonancia magnética nuclear (NMR) para obtener información acerca de su dinamismo. Dado que es una proteína grande, se utilizó una estrategia en la que se combinó el marcaje selectivo y el uso de experimentos TROSY-HSQC.
Posteriormente, se realizó el estudio de la DPP IV en presencia de sus inhibidores, para observar como estos afectan a la estructura proteica.
Después, se realizó la búsqueda de inhibidores de la DPP IV a partir de extractos de plantas medicinales. De nuestra colección, se seleccionó el extracto de la planta AP-3 para un análisis en profundidad. Se detectaron dos inhibidores de la proteasa. El más potente, AP-3-a, se caracterizó cómo un inhibidor parabólico.
Después se llevó a cabo el estudio del complejo DPP IV/AP-3-a por NMR.
En cuanto a la POP, se realizó la búsqueda de inhibidores mediante cribado de alto rendimiento (HTS). De los 4,500 compuestos testados se obtuvo un total de 73 hits en el ensayo de polarización de la fluorescencia (FP). La validación de estas moléculas mediante docking, clustering y ensayos enzimáticos, permitió identificar seis potentes inhibidores de POP. Uno de ellos, HTS-75, se caracterizó como un inhibidor parabólico.
Esta es la primera vez que se describe un inactivador de este tipo para POP.
Finalmente, en cuanto a las catepsinas L y B, se cribó una librería de peptidil aril vinil sulfonas. Entre las 20 moléculas testadas se encontró un potente inhibidor irreversible de la catepsina L, el PAVS-20. Además, se realizó un estudio de docking que permitió evaluar las preferencias de los subsitios de las dos proteasas.
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Dou, Dengfeng. "Mammalian and viral protease inhibitors." Diss., Wichita State University, 2010. http://hdl.handle.net/10057/3281.
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Chronic Obstructive Pulmonary Disease (COPD) is currently the fourth leading cause of death in the US. COPD is a multi-factorial disorder characterized by an oxidant/antioxidant imbalance, inflammation, a protease/antiprotease imbalance and apoptosis. This dissertation describes a general strategy for the design, synthesis and biochemical evaluation of dual function inhibitors which could potentially interrupt the above disorder, thereby enhancing the treatment of COPD. An example of this type inhibitor based on the 1,2,5-thiadiazolidin-3-one scaffold has been proven effective against both human neutrophil elastase (HNE) and caspase-1, two key enzymes responsible for elastin degradation and inflammation, respectively. In addition, an X-ray crystal structure and a high resolution mass spectrum of inhibitor bonded HNE have proven the proposed mechanism of HNE inactivation. Furhtermore, simple reversible competitive inhibitors of COPD-related enzymes (HNE and proteinase 3) have also been designed, synthesized and evaluated biochemically.
West Nile virus and Dengue virus are recognized as a major health threat that affects millions of people worldwide. However, there is currently no treatment or vaccine available for the virus infection. This dissertation describes the design, synthesis and biochemical evaluation of reversible competitive inhibitors of both West Nile virus and Dengue virus NS2B-NS3 protease. Combinatorial chemistry and click chemistry methods have been used in the design of the protease inhibitor and the identified hit was optimized using computational programs (AutoDock4 and SYBYL). Several more hits were identified during the optimization and further development could potentially lead to very potent inhibitors of NS2B-NS3 protease with good pharmacokinetics and oral bioavailability.<br>Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry
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Lee, Victor. "Synthesis of HIV protease inhibitors." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291434.
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Chong, Sannie Siaw Foong. "Anisotropic potential HIV-1 protease inhibitors." Thesis, University of Hull, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327289.
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Eagling, Victoria Anne. "HIV protease inhibitors and drug disposition." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484290.
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Swedberg, Joakim Erik. "Rational design of serine protease inhibitors." Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/48131/1/Joakim_Swedberg_Thesis.pdf.
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Proteases regulate a spectrum of diverse physiological processes, and dysregulation of proteolytic activity drives a plethora of pathological conditions. Understanding protease function is essential to appreciating many aspects of normal physiology and progression of disease. Consequently, development of potent and specific inhibitors of proteolytic enzymes is vital to provide tools for the dissection of protease function in biological systems and for the treatment of diseases linked to aberrant proteolytic activity. The studies in this thesis describe the rational design of potent inhibitors of three proteases that are implicated in disease development. Additionally, key features of the interaction of proteases and their cognate inhibitors or substrates are analysed and a series of rational inhibitor design principles are expounded and tested. Rational design of protease inhibitors relies on a comprehensive understanding of protease structure and biochemistry. Analysis of known protease cleavage sites in proteins and peptides is a commonly used source of such information. However, model peptide substrate and protein sequences have widely differing levels of backbone constraint and hence can adopt highly divergent structures when binding to a protease’s active site. This may result in identical sequences in peptides and proteins having different conformations and diverse spatial distribution of amino acid functionalities. Regardless of this, protein and peptide cleavage sites are often regarded as being equivalent. One of the key findings in the following studies is a definitive demonstration of the lack of equivalence between these two classes of substrate and invalidation of the common practice of using the sequences of model peptide substrates to predict cleavage of proteins in vivo. Another important feature for protease substrate recognition is subsite cooperativity. This type of cooperativity is commonly referred to as protease or substrate binding subsite cooperativity and is distinct from allosteric cooperativity, where binding of a molecule distant from the protease active site affects the binding affinity of a substrate. Subsite cooperativity may be intramolecular where neighbouring residues in substrates are interacting, affecting the scissile bond’s susceptibility to protease cleavage. Subsite cooperativity can also be intermolecular where a particular residue’s contribution to binding affinity changes depending on the identity of neighbouring amino acids. Although numerous studies have identified subsite cooperativity effects, these findings are frequently ignored in investigations probing subsite selectivity by screening against diverse combinatorial libraries of peptides (positional scanning synthetic combinatorial library; PS-SCL). This strategy for determining cleavage specificity relies on the averaged rates of hydrolysis for an uncharacterised ensemble of peptide sequences, as opposed to the defined rate of hydrolysis of a known specific substrate. Further, since PS-SCL screens probe the preference of the various protease subsites independently, this method is inherently unable to detect subsite cooperativity. However, mean hydrolysis rates from PS-SCL screens are often interpreted as being comparable to those produced by single peptide cleavages. Before this study no large systematic evaluation had been made to determine the level of correlation between protease selectivity as predicted by screening against a library of combinatorial peptides and cleavage of individual peptides. This subject is specifically explored in the studies described here. In order to establish whether PS-SCL screens could accurately determine the substrate preferences of proteases, a systematic comparison of data from PS-SCLs with libraries containing individually synthesised peptides (sparse matrix library; SML) was carried out. These SML libraries were designed to include all possible sequence combinations of the residues that were suggested to be preferred by a protease using the PS-SCL method. SML screening against the three serine proteases kallikrein 4 (KLK4), kallikrein 14 (KLK14) and plasmin revealed highly preferred peptide substrates that could not have been deduced by PS-SCL screening alone. Comparing protease subsite preference profiles from screens of the two types of peptide libraries showed that the most preferred substrates were not detected by PS SCL screening as a consequence of intermolecular cooperativity being negated by the very nature of PS SCL screening. Sequences that are highly favoured as result of intermolecular cooperativity achieve optimal protease subsite occupancy, and thereby interact with very specific determinants of the protease. Identifying these substrate sequences is important since they may be used to produce potent and selective inhibitors of protolytic enzymes. This study found that highly favoured substrate sequences that relied on intermolecular cooperativity allowed for the production of potent inhibitors of KLK4, KLK14 and plasmin. Peptide aldehydes based on preferred plasmin sequences produced high affinity transition state analogue inhibitors for this protease. The most potent of these maintained specificity over plasma kallikrein (known to have a very similar substrate preference to plasmin). Furthermore, the efficiency of this inhibitor in blocking fibrinolysis in vitro was comparable to aprotinin, which previously saw clinical use to reduce perioperative bleeding. One substrate sequence particularly favoured by KLK4 was substituted into the 14 amino acid, circular sunflower trypsin inhibitor (SFTI). This resulted in a highly potent and selective inhibitor (SFTI-FCQR) which attenuated protease activated receptor signalling by KLK4 in vitro. Moreover, SFTI-FCQR and paclitaxel synergistically reduced growth of ovarian cancer cells in vitro, making this inhibitor a lead compound for further therapeutic development. Similar incorporation of a preferred KLK14 amino acid sequence into the SFTI scaffold produced a potent inhibitor for this protease. However, the conformationally constrained SFTI backbone enforced a different intramolecular cooperativity, which masked a KLK14 specific determinant. As a consequence, the level of selectivity achievable was lower than that found for the KLK4 inhibitor. Standard mechanism inhibitors such as SFTI rely on a stable acyl-enzyme intermediate for high affinity binding. This is achieved by a conformationally constrained canonical binding loop that allows for reformation of the scissile peptide bond after cleavage. Amino acid substitutions within the inhibitor to target a particular protease may compromise structural determinants that support the rigidity of the binding loop and thereby prevent the engineered inhibitor reaching its full potential. An in silico analysis was carried out to examine the potential for further improvements to the potency and selectivity of the SFTI-based KLK4 and KLK14 inhibitors. Molecular dynamics simulations suggested that the substitutions within SFTI required to target KLK4 and KLK14 had compromised the intramolecular hydrogen bond network of the inhibitor and caused a concomitant loss of binding loop stability. Furthermore in silico amino acid substitution revealed a consistent correlation between a higher frequency of formation and the number of internal hydrogen bonds of SFTI-variants and lower inhibition constants. These predictions allowed for the production of second generation inhibitors with enhanced binding affinity toward both targets and highlight the importance of considering intramolecular cooperativity effects when engineering proteins or circular peptides to target proteases. The findings from this study show that although PS-SCLs are a useful tool for high throughput screening of approximate protease preference, later refinement by SML screening is needed to reveal optimal subsite occupancy due to cooperativity in substrate recognition. This investigation has also demonstrated the importance of maintaining structural determinants of backbone constraint and conformation when engineering standard mechanism inhibitors for new targets. Combined these results show that backbone conformation and amino acid cooperativity have more prominent roles than previously appreciated in determining substrate/inhibitor specificity and binding affinity. The three key inhibitors designed during this investigation are now being developed as lead compounds for cancer chemotherapy, control of fibrinolysis and cosmeceutical applications. These compounds form the basis of a portfolio of intellectual property which will be further developed in the coming years.
Books on the topic "Protease inhibitors"
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Cheronis, J. C., and J. E. Repine, eds. Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0.
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1926-, Katunuma Nobuhiko, ed. Medical aspects of proteases and protease inhibitors. IOS Press, 1997.
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B, Banner Carl D., and Nixon Ralph A, eds. Proteases and protease inhibitors in Alzheimer's disease pathogenesis. New York Academy of Sciences, 1992.
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A, Nixon Ralph, Banner Carl D. B, and New York Academy of Sciences., eds. Proteases and protease inhibitors in Alzheimer's disease pathogenesis. NewYork Academy of Sciences, 1992.
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Cheronis, John Chris Dion, 1951- and Repine John E, eds. Proteases, protease inhibitors, and protease-derived peptides: Importance in human pathophysiology and therapeutics. Birkhäuser Verlag, 1993.
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1953-, Ogden Richard C., and Flexner Charles W. 1956-, eds. Protease inhibitors in AIDS therapy. Marcel Dekker, 2001.
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Chang, Henry E. HIV protease inhibitor report. 2nd ed. National AIDS Treatment Advocacy Project, 1996.
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Troll, Walter, and Ann R. Kennedy, eds. Protease Inhibitors as Cancer Chemopreventive Agents. Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2882-1.
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Walter, Troll, and Kennedy Ann R, eds. Protease inhibitors as cancer chemopreventive agents. Plenum Press, 1993.
Find full textBook chapters on the topic "Protease inhibitors"
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Wagner, Todd. "Protease Inhibitors." In Mental Health Practitioner's Guide to HIV/AIDS. Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4614-5283-6_69.
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Rosenthal, Philip J. "Protease Inhibitors." In Antimalarial Chemotherapy. Humana Press, 2001. https://doi.org/10.1007/978-1-59259-111-4_18.
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Powers, James C., Shinjiro Odake, Jozef Oleksyszyn, et al. "Proteases—Structures, Mechanism and Inhibitors." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_1.
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Kucz, Nicolette, Michael Meltzer, and Michael Ehrmann. "Periplasmic Proteases and Protease Inhibitors." In The Periplasm. ASM Press, 2014. http://dx.doi.org/10.1128/9781555815806.ch9.
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Steffens, Gerd J., Regina Heinzel-Wieland, Derek Saunders, et al. "Oxidation Resistant Muteins of Antileukoproteinase as Potential Therapeutic Agents." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_10.
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Colman, Robert W. "Factor XII Activation and Inhibition in Inflammation." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_11.
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Stewart, John M. "The Kinin System in Inflammation." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_12.
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Maeda, Hiroshi, Takaaki Akaike, Yoshifumi Sakata, and Keishi Maruo. "Role of Bradykinin in Microbial Infection: Enhancement of Septicemia by Microbial Proteases and Kinin." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_13.
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Whalley, E. T., and J. C. Cheronis. "Kinin Antagonists as Human Therapeutics." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_14.
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Niedbala, Michael J. "Cytokine Regulation of Endothelial Cell Extracellular Proteolysis." In Proteases, Protease Inhibitors and Protease-Derived Peptides. Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-7397-0_15.
Full textConference papers on the topic "Protease inhibitors"
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Carrell, R. W., P. D. Christey, and D. R. Boswell. "SERPINS: ANTITHROMBIN AND OTHER INHIBITORS OF COAGULATION AND FIBRINOLYSIS. EVIDENCE FROM AMINO ACID SEQUENCES." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642896.
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A number of the key inhibitors of coagulation and fibrinolysis have recently been shown to be members of the same superfamily of serine protease inhibitors, the serpins. The archetypes of the group are alpha-l-antitrypsin and antithrombin and it includes antiplasmin, C1-inhibitor, heparin cofactor II and the newly recognised inhibitors of plasminogen activators and activated Protein C. Alignment of their structures shows that they have the same skeletal three-dimensional conformation and, by inference, the same general function mechanisms.The serpins have a reactive centre, primarily dependent on a single amino acid, exteriorly placed on a stressed peptide loop. This functions by offering the cognate protease a high-affinity substrate that resists complete cleavage to form a tight 1:1 complex of inhibitor and protease that is subsequently removed from the circulation. The loop is vulnerable to cleavage with resulting loss of inhibitory activity. This irreversible switch is utilised: pathologically by venom and invasive bacterial proteases; and physiologically by the neutrophil leucocyte to modify local inflammatory responses. These mechanisms contribute to the changes seen in DIC and the shock syndromes.Modelling of antithrombin indicates the likely topological features involved in the binding of heparin, namely a sphere of positive charge centred on the A and D helices and involving Arg 47, Lys 125, Arg 129 and probably Arg 132 and Lys 133.Because the serpins are largely dependent for their specificityon a single amino acid it is now possible to precisely tailor inhibitory activity by site specific mutation. This has been used to produce recombinant antitrypsins that function as an improved inhibitor of neutrophil proteases (valine or leucine reactive centre), or as an analogue of antithrombin (arginine reactive centre). An elegant application of this approach is the engineered mutants of antiplasmin recently described by Holmes, Collen and colleagues (Leuven).
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Baker, J. B., M. P. McGrogan, C. Simonsen, R. L. Gronke, and B. W. Festoff. "STRUCTURE AND PROPERTIES OF PROTEASE NEXIN I." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644765.
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Human foreskin fibroblasts secrete several different serine protease inhibitors which differ in size and protease specificities. These proteins, called protease nexins (PNs) all form SDS-resistant complexes with their protease targets. Fibroblast surface receptors recognize the protease-PN complexes and mediate their delivery to lysosomes. PNI is a 45 kilodalton glycoprotein that rapidly inhibits several arg or lys-specific proteases including trypsin, thrombin, and urokinase (k assoc.∼ 4×l06,∼ 6×105 and ∼ 2×105, m−1s−1 respectively). Like antithrombin III, PNI binds heparin and inhibits thrombin at a vastly accelerated rate in the presence of this glycoaminoglycan. Immunofluorescence studies show that in addition to secreting PNI foreskin fibroblasts carry this inhibitor on their surfaces. PNI cDNA has been cloned and sequenced. A mixed oligonucleotide probe derived from PNI N-terminal sequence was used to probe a foreskin fibroblast cDNA library constructed with λGT10. Identification of PNI cDNAs has been verified by sequencing and by expressing active PNI protein in mammalian cells. The full amino acid sequence of PNI, deduced from cDNA sequencing, is 392 residues long and has 30% homology to antithrombin III. An arg-ser pair 32 residues from the C-terminus of the inhibitor is proposed as the reactive center P1-P1 residues. In the hinge region a lys residue is present in a position occupied by a ginor glu residue in other serpins. PNI mRNA exists in 2 slightly different forms:One (αPNI) yields a thr-arg-ser sequence wherethe other βPNI) yields a thr-thr-gly-ser sequence. The presence of the appropriate splice acceptor sites in the genome indicates that these forms are generated from a single gene by alternative splicing. Expressed aPNI and 0PNI proteins both bind thrombin and urokinase. In foreskin fibroblaststhe α form of PNI mRNA predominates over the β form by about 2:1. In foreskin fibroblast cultures secreted PNI inhibits the mitogenic response to thrombin and regulate secreted urokinase. Purified PNI added to human fibrosarcoma (HT1080) cells inhibitsthe tumor cell-mediated destruction of extracellular matrix and transiently, but dramatically, inhibits tumor cell growth. PNI or PNI-like inhibitors may function at multiple physiological sites. The β form of PNI is virtually identical to a glia-derived neurite promoting factor, the cDNA for which has been recently cloned and sequenced by Gloor et al (1). The neurite outgrowth activity of PNI may result from inhibition of a thrombin-like protease that is associated with neurons, since a number of thrombin inhibitors stimulate neurite extension. Recent immunofluoresence experiments, carried out with D. Hantai (Inserm; Paris) demonstrate that anti-PNI antibody intensely stains neuromuscular synapses. In addition, a PNI-like inhibitor is associated with platelets. At low (0.5 nM <) 125I-thrombin concentrations formation of 125I-thrombin-platelet PNI complexes accounts for most of the specific binding of 125I-thrombin to platelets (2). Although the platelet-associated form of PNI is electrophoretically and immunologically indistinguishable from fibroblast PNI, it does not bind urokinase, suggesting that it may be distinct.(1) Gloor, S., K. Odink, J. Guenther, H. Nick, and D. Monard. (1986) Cell 47:687-693.(2) Gronke, R.S., B.L. Bergman, and J.B. Baker. (1987) J. Biol. Chem. (in press)
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Bosenbecker, Juliano, Adriana M. das Neves, Daniela P. Gouvêa, Maieli C. Soares, and Wilson Cunico. "Synthesis of protease inhibitors derivatives." In 14th Brazilian Meeting on Organic Synthesis. Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-14bmos-r0059-2.
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Sas, G. "DEFECTS IN SERINE PROTEASE INHIBITORS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643714.
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Several serine protease inhibitorsof plasma inhibit the activated coagulation enzymes but only antithrombin III(AT-III)and heparin cofactor II (HC-II) are implicated in the pathogenesisof the familial thrombosis. Since thefirst publication (1965) many thrombophilic families with reduced AT-III synthesis have been investigated. These studies have proved that the disorder is associated with a high risk forvenous thrombosis and the inheritanceis autosomal dominant. The AT-III activity in the plasma of the affected patients is about 50% of the normalvalue.In recent years the heterogeneity of the inherited AT-III deficiency has been verified. The various AT-III abnormalities are not mere interestingrarities but they provide naturally occurring models for the solution of theoretical problems such as the function of AT-III molecule, the physiological significance of heparin, etc. Furthermore, the clinical manifestationof the particular variants greatly differs from symptomless abnormality tosevere thrombotic cases.In the majority of cases, reduced functional activity is accompanied with a parallel decrease of antigen concentration of AT-III. This is the characteristic feature of the quantitative or Type I ("classical")AT-III deficiency. By means of crossed immunoelectrophoresis, electro-focussing and recombinant DNA techniques the heterogeneity of this group has been established. In one subgroup (Type la) AT-III molecules are normal as regards their biochemical characteristics. In Type lb, subnormal AT-IIIquantity is accompanied with decreased heparin affinity. Differentiation of these subgroups has practical consequences: therapeutic concentrations of heparin apparently does not decrease AT-III level in the plasma of patients with Type lb AT-III deficiency.The other main form is the qualitative deficiency of AT-III (Type II) which is characterised by reduced functional activity at normal antigen concentration. In general, two populations of AT-III molecules can be detected in the blood of these patients: a normal and an abnormal one. Up till now at least 24 different abnormalities were found and designatedwith toponymes. These disorders can be classified with relatively simple laboratory methods such as functional anti-IIaXaFirstDepartment of Medicine, Postgraduate Medical University, Budapest, Hungary.arin cofactor activity, crossed immunoelectrophoresiswith and without heparin, heparin-affinity chromatography. Type na is characterised by profound structural changes of the molecule,variably: reflected in reduced inactivation of F Ha and F Xa, abnormal heparin-AT-III reaction and aberrant immunochemical structure Seven different abnormalities fall into this group (Budapest I, Tokyo, MalmÖ, Chicago, Milano, Trento and Northwick Park). The last three abnormalities are very similar.In Type lib an isolated defect of protease inactivation can be detected and an isolated disturbance of the active centre ofthe molecule is assumed.Until now 6 apparently different variants belonging to this group have been described. (Aalborg, Vicenza, Denver, Hvidovre, Charleville, Milano 2.) Type lie abnormality is characterised by an isolated defect of the heparin-AT-III reaction. In these cases a disturbance of the heparin binding site(s) is assumed. Eleven families with this type of abnormality have been recorded (Ann Arbor, Basel, Paris 1 and 2, Toyama* Tours, Padova I and 2, Algers, Fontainebleu and Budapest 2). This subgroup is heterogeneous in respect ofheparin affinity: in the majority of cases the abnormal AT-III molecules have no heparin affinity at all while in rare cases (such as Basel, Budapest 2) they have reduced affinity.TheType lie AT-III deficiency has several distinctive features compared with the other subtypesJClinically, the thromboembolic complications are rare: in 4 families thrombosis has notoccurred at all. Only one member in each of 4 other families had thrombosis. In 3 families homozygous patients suffered severe thrombosis in young age and/or in unusual localisations (intraarterial, intracardiac, etc.) butthe other heterozygous members were free of thrombotic symptoms. No increased intravascular coagulation could be detected in Type lie heterozygous cases incontrast to the "classical" AT-III deficiency.These observations suggest a different mechanism and clinical manifestation of the deficiency of progressiveserine protease inactivation and of heparin cofactor activity. In case of progressive inactivation, reduction of 50% of the activity predisposes mainly to venous thrombosis as a consequence of the hypercoagulability of theblood. The isolated reduction of heparin cofactor activity seems to bringabout thrombosis in any part of the vascular system, but only if this reduction is as severe as that of the coagulant factors in case of coagulopathies.In accordance with this finding, rare cases of HCII deficiency give rise to thrombosis in both the arteries and the veins. Heparin cofactor activities may play an important role in the antithrombotic mechanism along theendothelial surface of the whole vascular system.
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Tans, G., T. Janssen-Claessen, J. Rosing, and J. H. Griffin. "APPLICATION OF SPECIFIC SERINE PROTEASE INHIBITORS IN ASSAYS FOR ACTIVATED CONTACT FACTORS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643301.
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We developed amidolytic assays to determine human Factor Xlla, Factor XIa and plasma kallikrein in mixtures containing variable amounts of each enzyme. The commercially available chromogenic substrates pro-phe-arg-pNA (S2302 or chromozym PK), glu-pro-arg-pNA (S2366), ile-glu-(piperidyl)-gly-arg-pNA (S2337), and ile-glu-gly-arg-pNA (S2222) were tested for their suitability as substrates in these assays. 8-Factor Xlla, Factor XIa and plasma kallikrein each exhibit considerable activity towards a number of these substrates. This precludes direct quantitation of the individual enzymes when large amounts of other activated contact factors are present. Several serine protease inhibitors were tested on their ability to selectively inhibit those contact factors that may interfere with the factor tested for. Soybean trypsin inhibitor efficiently inhibits kallikrein, inhibits Factor XIa at moderate concentrations, but did not affect the amidolytic activity of Factor Xlla. Therefore, this inhibitor can be used to abolish a kallikrein and Factor XIa contribution in a Factor Xlla assay. We also report the rate constants of inhibition of contact activation factors by three different chloromethylketones. D-phe-pro-arg-CH 2 Cl was moderately active against contact factors (k - 2271 M-ls-1 at pH 8.3) but showed no differences in specif ity. D-phe-phe-arg-CH2 Cl was a very efficient inhibitor of kallikrein (k = 118,000 M-ls-1 at pH 8.3) whereas it slowly inhibited Factor Xlla (k = 1389 M-ls-1) and Factor XIa (k = 110 M-ls-1). Also dansyl-glu-gly-arg-CH2Cl was more reactive towards kallikrein (k 15,662 M-ls-1) than towards Factor Xlla (k = 462 M-ls-1) and Factor XIa (k = 63 M-ls-1). Since phe-phe-arg-CH2Cl is highly specific for kallikrein it can be used in a Factor XIa assay to selectively inhibit kallikrein. Based on the catalytic efficiencies of chromogenic substrate conversion and the inhibition characteristics of serine protease inhibitors and chloromethyl ketones we were able to develop quantitative assays for Factor Xlla, Factor XIa and kallikrein in mixtures of contact activation factors.
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Sidorova, A. P., and A. V. Bakunovich. "ANTIRETROVIRAL DRUGS AS POTENTIAL INHIBITORS OF SARS-COV-2 Mpro." In SAKHAROV READINGS 2022: ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute of Belarusian State University, 2022. http://dx.doi.org/10.46646/sakh-2022-2-31-34.
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Ritonavir, nelfinavir and lopinavir are a group of protease inhibitors. These inhibitors are widely used in combination with other protease inhibitors in the therapy and prevention of human immunodeficiency virus. Also, the combination of these inhibitors seems to be an effective therapeutic agent that can affect the main protease of Mpro coronavirus and, thus, provide long-term suppression of viral load in the disease of severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2).
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de Agostini, A., F. Barja, S. Carrel, P. C. Harpel, and M. Schapira. "C1 -INHIBITOR: STRUCTURE-ACTIVITY RELATIONSHIPS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642903.
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Cl-inhibitor [C1 -In] and other protease inhibitors of the serpin superfamily inactivate serine proteases by forming bimolecular enzyme-inhibitor complexes, a reaction that is associated with changes in the inhibitor conformation. To determine the significance of these changes, we have examined the influence of various treatments on the binding to C1-In of monoclonal antibody 4C3. This antibody was previously shown to bind to an epitope created during the reaction of C1-In with the Arg-specific protease plasma kallikrein [K]: the site for 4C3 was expressed on the K-C1-In complex, on C1-In cleaved at position Pi and released from K-C1-In [C1-In*], but not on unreacted C1-In. The binding of 4C3 to the various forms of C1-In was now measured by radioimmunoassay and Western blot. Following inactivation by C1-In of the Arg-specific enzymes factor XII active fragment [Xllf] or C1s, the binding site for 4C3 was detectable on XIIf-CI-In, C1s-C1-In and C1-In*. However, when K or Xllf were incubated with heat-inactivated C1-In, bo+h enzymes remained active, no complex was formed, and the site for 4C3 was not created. When C1-In was cleaved by neutrophil elastase [E] (a Met-orVal-specific protease that is not inhibited by C1 -In), the 1st cleavage product C1-In’ retained inhibitory activity (as shown by its ability to form a complex with Xllf) but did not bind 4C3. However, subsequent cleavage of C1-In’ by E at position P3 yielded C1-In’, a product which was inactive but bound 4C3. Thus, identical conformational changes of C1-In (as assessed by the emergence of the site for 4C3) are seen when Cl-In inactivates its target enzymes while being cleaved at Pi or when the inhibitor is catalytically inactivated by cleavage at P3. Therefore, these changes are necessary but not sufficient for observing enzyme inactivation.
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Strandberg, L., D. Lawrence, and T. Ny. "ISOLATION OF THE GENOMIC REGION CODING FOR TYPE-1 PLASMINOGEN ACTIVATOR INHIBITOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644439.
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The type-1 Plasminogen Activator Inhibitor (PAI-1) has recently been identified as a member of the Serine Protease Inhibitor family (SERPINS). This family of proteins contain many serine protease inhibitors but also functionally unrelated proteins like ovalbumin and anginotensinogen. PAI-1 inhibits both u-PA and t-PA and might therefore be an important regulator of the fibrinolytic system.In order to study the evolution of the Serpin family as well as PAI-1 gene expression we have isolated the genomic region carrying the PAI-1 gene. A cDNA sequence for PAI-1 was used as probe to screen a human genomic library. When 2 million independent phages were screened, 13 positive clones were isolated. Characterisation of these clones showed that they could be divided into 3 overlapping groups covering a genomic region of approximately 30 kb. The gene was localized and characterized by restriction enzyme analysis, southern blotting using cDNA and oligomer probes, and DNA sequencing.
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Mahdiyah, Dede, and Bayu Mukti. "A Review: Protease Inhibitors From Sponge Jaspis Sp. Associated Bacteria." In Proceedings of the First National Seminar Universitas Sari Mulia, NS-UNISM 2019, 23rd November 2019, Banjarmasin, South Kalimantan, Indonesia. EAI, 2020. http://dx.doi.org/10.4108/eai.23-11-2019.2298399.
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Sprott, Kevin, and Paul Hanson. "Amino Acid-Derived Cyclic Phosphonamides as Potential HIV-Protease Inhibitors." In The 4th International Electronic Conference on Synthetic Organic Chemistry. MDPI, 2000. http://dx.doi.org/10.3390/ecsoc-4-01866.
Full textReports on the topic "Protease inhibitors"
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Haritos, George. The Effect of the Protease Inhibitors Ritonavir on the Rate of Metabolism of Midazolam. Defense Technical Information Center, 1999. http://dx.doi.org/10.21236/ad1012139.
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Farady, Christopher J. Structural Characterization and Determinants of Specificity of Single-Chain Antibody Inhibitors of Membrane-Type Serine Protease 1. Defense Technical Information Center, 2008. http://dx.doi.org/10.21236/ada486728.
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Farady, Christopher J. Structural Characterization and Determinants of Specificity of Single-Chain Antibody Inhibitors of Membrane-Type Serine Protease 1. Defense Technical Information Center, 2006. http://dx.doi.org/10.21236/ada462384.
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Farady, Christopher J. Structural Characterization and Determinants of Specificity of Single- Chain Antibody Inhibitors of Membrane-Type Serine Protease 1. Defense Technical Information Center, 2007. http://dx.doi.org/10.21236/ada471511.
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Birk, Yehudit, Karl J. Kramer, Shalom W. Applebaum, and G. R. Reeck. Structure and Function of Protease Inhibitors from Legume Seeds and Cereal Grains and their Interaction with Digestive Enzymes of Stored Product Insects. United States Department of Agriculture, 1986. http://dx.doi.org/10.32747/1986.7566729.bard.
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Yongchaitrakul, Tassanee, and Prasit Pavasant. Effect of LPS of Actinobacillus actinomycetemcomitans lipopolysaccharide on matrix metalloproteinase-2 and changes of RANKL and OPG in HPDL cell. Chulalongkorn University, 2004. https://doi.org/10.58837/chula.res.2004.13.
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Background: The LPS of A.actinomycetemcomitans is one of the major pathogenic factors in periodontal disease. It induces secretion of pro-inflammatory cytokines and involves in alveolar bone destruction. We hypothesized that the LPS of A.actinomycetemcomitans could affect the activation of MMP-2 and the expression of RANKL and OPG in HPDL cells leading to the destruction of periodontium. Methods: HPDL cells were cultured in serum-free medium with or without the LPS of A.actinomycetemcomitans for 36 hours. The activation of MMP-2 was analyzed by zymography. Changes of the expression of RANKL and OPG were examined by reverse transcription-polymerase chain reaction and supported by western blot analysis. Results: The activation of MMP-2 could be induced by the LPS of A.actinomycetemcomitans in HPDL cells and could be inhibited by a serine protease inhibitor. The result suggested that the LPS might activate MMP-2 through a serine protease-dependent pathway. The activation was also blocked by NF-kB inhibitor, which indicated the involvement of NF-kB. The up-regulation of RANKL but not OPG by the LPS was found in both transcription and translation and could be abolished by Indomethacin. In addition, serine protease inhibitor also inhibited the up-regulation of RANKL, suggesting the activity of serine protease.
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Lin, Chen-Yong. An Epithelial-Derived, Integral Membrane, Kunitz-Type Serine Protease Inhibitor in Breast Cancer. Defense Technical Information Center, 2002. http://dx.doi.org/10.21236/ada410178.
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