Journal articles: 'Biotin-Streptavidin'

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Wu, Sau-Ching, and Sui-Lam Wong. "Engineering of a Bacillus subtilis Strain with Adjustable Levels of Intracellular Biotin for Secretory Production of Functional Streptavidin." Applied and Environmental Microbiology 68, no. 3 (March 2002): 1102–8. http://dx.doi.org/10.1128/aem.68.3.1102-1108.2002.

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ABSTRACT Streptavidin is a biotin-binding protein which has been widely used in many in vitro and in vivo applications. Because of the ease of protein recovery and availability of protease-deficient strains, the Bacillus subtilis expression-secretion system is an attractive system for streptavidin production. However, attempts to produce streptavidin using B. subtilis face the problem that cells overproducing large amounts of streptavidin suffer poor growth, presumably because of biotin deficiency. This problem cannot be solved by supplementing biotin to the culture medium, as this will saturate the biotin binding sites in streptavidin. We addressed this dilemma by engineering a B. subtilis strain (WB800BIO) which overproduces intracellular biotin. The strategy involves replacing the natural regulatory region of the B. subtilis chromosomal biotin biosynthetic operon (bioWAFDBIorf2) with an engineered one consisting of the B. subtilis groE promoter and gluconate operator. Biotin production in WB800BIO is induced by gluconate, and the level of biotin produced can be adjusted by varying the gluconate dosage. A level of gluconate was selected to allow enhanced intracellular production of biotin without getting it released into the culture medium. WB800BIO, when used as a host for streptavidin production, grows healthily in a biotin-limited medium and produces large amounts (35 to 50 mg/liter) of streptavidin, with over 80% of its biotin binding sites available for future applications.

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Stayton, Patrick S., Stefanie Freitag, Lisa A. Klumb, Ashutosh Chilkoti, Vano Chu, Julie E. Penzotti, Richard To, et al. "Streptavidin–biotin binding energetics." Biomolecular Engineering 16, no. 1-4 (December 1999): 39–44. http://dx.doi.org/10.1016/s1050-3862(99)00042-x.

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Soltani, Orkide, Mohammad Reza Bozorgmehr, and Mohammad Momen-Heravi. "Does the single-walled carbon nanotube affect the rate constant of binding of biotin to streptavidin? Molecular dynamics simulation perspective." Progress in Reaction Kinetics and Mechanism 44, no. 3 (June 18, 2019): 234–43. http://dx.doi.org/10.1177/1468678319825710.

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The interaction of biotin and streptavidin in the presence and absence of a carbon nanotube was studied by molecular dynamics simulation. With respect to the Arrhenius dependence of the rate constants with temperature, those of streptavidin–biotin complex formation ([Formula: see text]) and streptavidin–biotin complex dissociation ([Formula: see text]) were calculated from molecular dynamics simulation trajectories. Nanotube has reduced the amount of and k1and k1. However, the biotin position in streptavidin does not change much. The results obtained from MMPBSA calculations show that the contribution of the van der Waals forces to both systems (in the absence and presence of the nanotube) was greater than that of electrostatic forces. The presence of the nanotube also led to the reduction of van der Waals and electrostatic forces in the interaction of biotin with streptavidin. However, this reduction was greater for electrostatic forces. In the absence of a nanotube, there are four hydrogen bonds between streptavidin and biotin, which are related to the residues Ser27, Tyr43, Ser45 and Ser88. In the presence of the nanotube, the hydrogen bonding of biotin with Ser45 is removed.

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De Odrowaz Piramowicz, Marzena, Paweł Czuba, Marta Targosz, Kvetoslava Burda, and Marek Szymoński. "Dynamic force measurements of avidin-biotin and streptavdin-biotin interactions using AFM." Acta Biochimica Polonica 53, no. 1 (January 12, 2006): 93–100. http://dx.doi.org/10.18388/abp.2006_3367.

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Using atomic force microscopy (AFM) we performed dynamic force measurements of the adhesive forces in two model systems: avidin-biotin and streptavidin-biotin. In our experiments we used glutaraldehyde for immobilization of (strept)avidin on the tip and biotin on the sample surface. Such interface layers are more rigid than those usually reported in the literature for AFM studies, when (strept)avidin is coupled with biotinylated bovine albumin and biotin with agarose polymers. We determined the dependence of the rupture forces of avidin-biotin and streptavidin-biotin bonds in the range 300-9600 pN/s. The slope of a semilogarithmic plot of this relation changes at about 1700 pN/s. The existence of two different regimes indicates the presence of two activation barriers of these complexes during the dissociation process. The dissociation rates and activation energy barriers, calculated from the Bell model, for the avidin-biotin and streptavidin-biotin interactions are similar to each other for loading rates > 1700 pN/s but they are different from each other for loading rates < 1700 pN/s. In the latter case, the dissociation rates show a higher stability of the avidin-biotin complex than the streptavidin-biotin complex due to a larger outer activation barrier of 0.8 k(B)T. The bond-rupture force is about 20 pN higher for the avidin-biotin pair than for the streptavidin-biotin pair for loading rates < 1700 pN/s. These two experimental observations are in agreement with the known structural differences between the biotin binding pocket of avidin and of streptavidin.

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Zhu, Xianwei, and Hiroaki Shinohara. "Fluorescence Enhancement of Fluorescent Unnatural Streptavidin by Binding of a Biotin Analogue with Spacer Tail and Its Application to Biotin Sensing." Scientific World Journal 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/165369.

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We designed a novel molecular biosensing system for the detection of biotin, an important vitamin by the combination of fluorescent unnatural streptavidin with a commercialized biotin-(AC5)2-hydrazide. A fluorescent unnatural amino acid, BODIPY-FL-aminophenylalanine (BFLAF), was position-specifically incorporated into Trp120 of streptavidin by four-base codon method. Fluorescence of the Trp120BFLAF mutant streptavidin was enhanced by the addition of biotin-(AC5)2-hydrazide with the concentration dependent, whereas fluorescence enhancement was not observed at all by the addition of natural biotin. It was considered that the spacer tail of biotin-(AC5)2-hydrazide may disturb the fluorescence quenching of the Trp120BFLAF by Trp79 and Trp108 of the neighbor subunit. Therefore, biotin sensing was carried out by the competitive binding reaction of biotin-(AC5)2-hydrazide and natural biotin to the fluorescent mutant streptavidin. The fluorescence intensity decreased by increasing free biotin concentration. The result suggested that molecular biosensor for small ligand could be successfully designed by the pair of fluorescent mutant binding protein and ligand analogue.

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Gitlin, G., E. A. Bayer, and M. Wilchek. "Studies on the biotin-binding site of streptavidin. Tryptophan residues involved in the active site." Biochemical Journal 256, no. 1 (November 15, 1988): 279–82. http://dx.doi.org/10.1042/bj2560279.

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Streptavidin, the non-glycosylated bacterial analogue of the egg-white glycoprotein avidin, was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl (Hnb) bromide. As with avidin, complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per streptavidin subunit. Tryptic peptides obtained from an Hnb-modified streptavidin preparation were fractionated by reversed-phase h.p.l.c., and three major Hnb-containing peptide fractions were isolated. Amino acid and N-terminal sequence analysis revealed that tryptophan residues 92, 108 and 120 are modified and probably comprise part of the biotin-binding site of the streptavidin molecule. Unlike avidin, the modification of lysine residues in streptavidin failed to result in complete loss of biotin-binding activity. The data imply subtle differences in the fine structure of the respective biotin-binding sites of the two proteins.

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Jeon, Byeong Jun, Sulhee Kim, Min-Seok Kim, Ji-Ho Lee, Beom Seok Kim, and Kwang Yeon Hwang. "Insights into the structure of mature streptavidin C1 from Streptomyces cinnamonensis reveal the self-binding of the extension C-terminal peptide to biotin-binding sites." IUCrJ 8, no. 2 (January 11, 2021): 168–77. http://dx.doi.org/10.1107/s2052252520015675.

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The members of the avidin protein family are well known for their high affinity towards D-biotin and their structural stability. These properties make avidins a valuable tool for various biotechnological applications. In the present study, two avidin-like biotin-binding proteins (named streptavidin C1 and C2) from Streptomyces cinnamonensis were newly identified while exploring antifungal proteins against Fusarium oxysporum f. sp. cucumerinum. Streptavidin C1 reveals a low correlation (a sequence identity of approximately 64%) with all known streptavidins, whereas streptavidin C2 shares a sequence identity of approximately 94% with other streptavidins. Here, the crystal structures of streptavidin C1 in the mature form and in complex with biotin at 2.1 and 2.5 Å resolution, respectively, were assessed. The overall structures present similar tetrameric features with D 2 symmetry to other (strept)avidin structures. Interestingly, the long C-terminal region comprises a short α-helix (C-Lid; residues 169–179) and an extension C-terminal peptide (ECP; residues 180–191) which stretches into the biotin-binding sites of the same monomer. This ECP sequence (–180VTSANPPAS188–) is a newly defined biotin-binding site, which reduces the ability to bind to (strept)avidin family proteins. The novel streptavidin C1 could help in the development of an engineered tetrameric streptavidin with reduced biotin-binding capacity as well as other biomaterial tools.

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Buckland, R. M. "Strong signals from streptavidin–biotin." Nature 320, no. 6062 (April 1986): 557–58. http://dx.doi.org/10.1038/320557a0.

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González, Martín, Luis A. Bagatolli, Izaskun Echabe, Jose L. R. Arrondo, Carlos E. Argaraña, Charles R. Cantor, and Gerardo D. Fidelio. "Interaction of Biotin with Streptavidin." Journal of Biological Chemistry 272, no. 17 (April 25, 1997): 11288–94. http://dx.doi.org/10.1074/jbc.272.17.11288.

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Maeda, Yoshiaki, Tomoko Yoshino, Masaaki Takahashi, Harumi Ginya, Junko Asahina, Hideji Tajima, and Tadashi Matsunaga. "Noncovalent Immobilization of Streptavidin on In Vitro- and In Vivo-Biotinylated Bacterial Magnetic Particles." Applied and Environmental Microbiology 74, no. 16 (June 20, 2008): 5139–45. http://dx.doi.org/10.1128/aem.00618-08.

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ABSTRACT Biotinylated magnetic nanoparticles were constructed by displaying biotin acceptor peptide (BAP) or biotin carboxyl carrier protein (BCCP) on the surface of bacterial magnetic particles (BacMPs) synthesized by Magnetospirillum magneticum AMB-1. BAP-displaying BacMPs (BAP-BacMPs) were extracted from bacterial cells and incubated with biotin and Escherichia coli biotin ligase. Then the in vitro biotinylation of BAP-BacMPs was confirmed using alkaline phosphatase-labeled antibiotin antibody. In contrast, BacMPs displaying the intact 149 residues of AMB-1 BCCP (BCCP-BacMPs) and displaying the COOH-terminal 78 residues of BCCP (BCCP78-BacMPs) were biotinylated in AMB-1 cells. The in vivo biotinylation of BCCP-BacMPs and BCCP78-BacMPs was thought to be performed by endogenous AMB-1 biotin ligase. Streptavidin was introduced onto biotinylated BacMPs by simple mixing. In an analysis using tetramethyl rhodamine isocyanate-labeled streptavidin, approximately 15 streptavidin molecules were shown to be immobilized on a single BCCP-BacMP. Furthermore, gold nanoparticle-BacMP composites were constructed via the biotin-streptavidin interaction. The conjugation system developed in this work provides a simple, low-cost method for producing biotin- or streptavidin-labeled magnetic nanoparticles. Various functional materials can be site selectively immobilized on these specially designed BacMPs. By combining the site-selective biotinylation technology and the protein display technology, more innovative and attractive magnetic nanomaterials can be constructed.

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Gitlin, G., E. A. Bayer, and M. Wilchek. "Studies on the biotin-binding sites of avidin and streptavidin. Tyrosine residues are involved in the binding site." Biochemical Journal 269, no. 2 (July 15, 1990): 527–30. http://dx.doi.org/10.1042/bj2690527.

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The involvement of tyrosine in the biotin-binding sites of the egg-white glycoprotein avidin and the bacterial protein streptavidin was examined by using the tyrosine-specific reagent p-nitrobenzenesulphonyl fluoride (Nbs-F). Modification of an average of about 0.5 mol of tyrosine residue/mol of avidin subunit caused the complete loss of biotin binding. This indicates that the single tyrosine residue (Tyr-33) in the avidin subunit is directly involved in the biotin-binding site and that its modification by Nbs also abolishes the binding properties of a neighbouring subunit. This suggests that the tyrosine residues of the egg-white protein may also contribute to the stabilization of the native protein structure. In streptavidin, however, the modification of an average of 3 mol of tyrosine residue/mol of subunit was required to inactivate completely the biotin-binding activity of the protein, but only 1 mol (average) of tyrosine residue/mol of subunit was protected in the presence of biotin. The difference between the h.p.l.c. elution profiles of the enzymic digests of Nbs-modified streptavidin and the Nbs-modified streptavidin-biotin complex revealed two additional fractions in the unprotected protein that contain Nbs-modified tyrosine residues. These residues, Tyr-43 (major fraction) and Tyr-54 (minor fraction), appear to contribute to the biotin-binding site in streptavidin.

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Piketty, Marie-Liesse, Dominique Prie, Frederic Sedel, Delphine Bernard, Claude Hercend, Philippe Chanson, and Jean-Claude Souberbielle. "High-dose biotin therapy leading to false biochemical endocrine profiles: validation of a simple method to overcome biotin interference." Clinical Chemistry and Laboratory Medicine (CCLM) 55, no. 6 (June 1, 2017): 817–25. http://dx.doi.org/10.1515/cclm-2016-1183.

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Abstract Background: High-dose biotin therapy is beneficial in progressive multiple sclerosis (MS) and is expected to be adopted by a large number of patients. Biotin therapy leads to analytical interference in many immunoassays that utilize streptavidin-biotin capture techniques, yielding skewed results that can mimic various endocrine disorders. We aimed at exploring this interference, to be able to remove biotin and avoid misleading results. Methods: We measured free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), parathyroid homrone (PTH), 25-hydroxyvitamin D (25OHD), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, C-peptide, cortisol (Roche Diagnostics assays), biotin and its main metabolites (liquid chromatography tandem mass spectrometry) in 23 plasmas from MS patients and healthy volunteers receiving high-dose biotin, and in 39 biotin-unsupplemented patients, before and after a simple procedure (designated N5) designed to remove biotin by means of streptavidin-coated microparticles. We also assayed fT4, TSH and PTH in the 23 high-biotin plasmas using assays not employing streptavidin-biotin binding. Results: The biotin concentration ranged from 31.7 to 1160 µg/L in the 23 high-biotin plasmas samples. After the N5 protocol, the biotin concentration was below the detection limit in all but two samples (8.3 and 27.6 μg/L). Most hormones results were abnormal, but normalized after N5. All results with the alternative methods were normal except two slight PTH elevations. In the 39 biotin-unsupplemented patients, the N5 protocol did not affect the results for any of the hormones, apart from an 8.4% decrease in PTH. Conclusions: We confirm that most streptavidin-biotin hormone immunoassays are affected by high biotin concentrations, leading to a risk of misdiagnosis. Our simple neutralization method efficiently suppresses biotin interference.

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Hsiao, Alexander P., and Michael J. Heller. "Electric-Field-Directed Self-Assembly of Active Enzyme-Nanoparticle Structures." Journal of Biomedicine and Biotechnology 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/178487.

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A method is presented for the electric-field-directed self-assembly of higher-order structures composed of alternating layers of biotin nanoparticles and streptavidin-/avidin-conjugated enzymes carried out on a microelectrode array device. Enzymes included in the study were glucose oxidase (GOx), horseradish peroxidase (HRP), and alkaline phosphatase (AP); all of which could be used to form a light-emitting microscale glucose sensor. Directed assembly included fabricating multilayer structures with 200 nm or 40 nm GOx-avidin-biotin nanoparticles, with AP-streptavidin-biotin nanoparticles, and with HRP-streptavidin-biotin nanoparticles. Multilayered structures were also fabricated with alternate layering of HRP-streptavidin-biotin nanoparticles and GOx-avidin-biotin nanoparticles. Results showed that enzymatic activity was retained after the assembly process, indicating that substrates could still diffuse into the structures and that the electric-field-based fabrication process itself did not cause any significant loss of enzyme activity. These methods provide a solution to overcome the cumbersome passive layer-by-layer assembly methods to efficiently fabricate higher-order active biological and chemical hybrid structures that can be useful for creating novel biosensors and drug delivery nanostructures, as well as for diagnostic applications.

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Gitlin, G., I. Khait, E. A. Bayer, M. Wilchek, and K. A. Muszkat. "Studies on the biotin-binding sites of avidin and streptavidin. A chemically induced dynamic nuclear polarization investigation of the status of tyrosine residues." Biochemical Journal 259, no. 2 (April 15, 1989): 493–98. http://dx.doi.org/10.1042/bj2590493.

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We applied the protein photochemically induced dynamic nuclear polarization (photo-c.i.d.n.p.) method to explore the conformation of the side chains of tyrosine, tryptophan and histidine residues in three biotin-binding proteins. The c.i.d.n.p. spectra of avidin, streptavidin and ‘core’ streptavidin were compared with those of their complexes with biotin and its derivatives. The data indicate that the single tyrosine residue (Tyr-33) of avidin is clearly inaccessible to the triplet flavin photo-c.i.d.n.p. probe. The same holds for all tryptophan and histidine side chains. Although the analogous Tyr-43 residue of streptavidin is also buried, at least three of the other tyrosine residues of this protein are exposed. The same conclusions apply to the truncated form of the protein, core streptavidin. As judged by the photo-c.i.d.n.p. results, complexing of avidin and streptavidin with biotin, N-epsilon-biotinyl-L-lysine (biocytin) or biotinyltyrosine has little or no effect on tyrosine accessibility in these proteins. Biotinyltyrosine can be used to probe the depth of the corresponding binding site. The accessibility of the tyrosine side chain of biotinyltyrosine in the complex demonstrates the exquisite fit of the biotin-binding cleft of avidin: only the biotin moiety appears to be accommodated, leaving the tyrosine side chain exposed.

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LI, JINHUA, XIANZHONG YU, THOMAS E. WAGNER, and YANZHANG WEI. "A biotin-streptavidin-biotin bridge dramatically enhances cell fusion." Oncology Letters 8, no. 1 (April 15, 2014): 198–202. http://dx.doi.org/10.3892/ol.2014.2067.

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Zotova, D. V., N. A. Grudinina, O. I. Antimonova, M. M. Shavlovsky, and D. S. Polyakov. "Localization and activity of recombinant streptavidin in cell fractions of Escherichia coli." Medical academic journal 18, no. 3 (September 15, 2018): 69–76. http://dx.doi.org/10.17816/maj18369-76.

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The authors provide a genetic construct for obtaining recombinant biologically active wild type streptavidin with high yield. Addition of leader peptide and oligohistidine sequence to the streptavidin sequence makes it possible to isolate soluble streptavidin from the culture medium and from the soluble fraction. Temperature conditions for inducing of protein synthesis were found to have a significant effect on the distribution profile of streptavidin between fractions. The obtained protein product is not contaminated with endogenous biotin. The provided method excludes denaturation and renaturation steps which are necessary for isolation of the desired product from inclusion bodies but substantially reduce the yield. Thus, the provided approach allows to increase the yield of biologically highly active strepatividin which is capable of binding biotin and biotin-containing compounds and can be used for various practical purposes.

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Jiang, Liping, Faying Li, Jinhui Feng, Ping Wang, Qing Liu, Yueyun Li, Yunhui Dong, and Qin Wei. "An optionality further amplification of an sandwich-type electrochemical immunosensor based on biotin–streptavidin–biotin strategy for detection of alpha fetoprotein." RSC Advances 6, no. 29 (2016): 24373–80. http://dx.doi.org/10.1039/c6ra01178k.

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Hollinshead, Michael, Jeremy Sanderson, and David J. Vaux. "Anti-biotin Antibodies Offer Superior Organelle-specific Labeling of Mitochondria over Avidin or Streptavidin." Journal of Histochemistry & Cytochemistry 45, no. 8 (August 1997): 1053–57. http://dx.doi.org/10.1177/002215549704500803.

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The mitochondrial matrix contains endogenously biotinylated proteins. These proteins can cause unexpected background signal when biotin–avidin- or biotin–streptavidin-based detection systems are used in immunocytochemistry. Here we show that this reactivity can be deliberately exploited, using a simple anti-biotin reagent, to obtain strong and highly specific labeling of mitochondria by both light and electron microscopy. The signal is substantially stronger than when either avidin or streptavidin is used to detect the endogenous biotin. These results confirm the accessibility of protein-bound endogenous biotin to exogenous probes, and localize the biotinylated enzymes to the mitochondrial matrix. (J Histochem Cytochem 45:1053–1057, 1997)

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Trambas, Christina, Zhong Lu, Tina Yen, and Ken Sikaris. "Depletion of biotin using streptavidin-coated microparticles: a validated solution to the problem of biotin interference in streptavidin–biotin immunoassays." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 55, no. 2 (June 29, 2017): 216–26. http://dx.doi.org/10.1177/0004563217707783.

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Background Biotin interference in streptavidin-based immunoassays causes widespread analytical distortions that may lead to clinical confusion, inappropriate patient management and, ultimately, adverse events. Its prevalence has increased recently due to the increased use of high-dose biotin therapy in specific patient groups (notably multiple sclerosis) and possibly the general community. Methods We have developed a method to deplete biotin from samples using the streptavidin-coated magnetic microparticles that are a component of most susceptible assays. Results We show that high concentrations of spiked biotin can be adequately depleted from serum using this approach, and that gross biochemical derangements can be restored to normality. We also show that biotin in samples derived from multiple sclerosis patients receiving 300 mg biotin daily can be adequately depleted to remove associated analytical interference and restore normal results. The method is applicable to competitive and sandwich immunoassays and importantly, because it does not change the volume of the sample, suitable for the measurement of free thyroid hormone assays. Application of the method does not significantly change the precision of measurement, and for the majority of analytes, the accuracy is not substantially altered. Conclusions Adopting this method enables laboratories to confirm biotin interference in the appropriate clinical setting. Moreover, it enables laboratories to remove the interference and report accurate and reliable results, without the need for patients to withhold beneficial therapy prior to blood tests. Until the biotin tolerance of susceptible assays is improved, our method gives laboratories a safe alternative for reporting results using streptavidin-based methods.

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Mzougui, Samy, Julien Favresse, Reza Soleimani, Catherine Fillée, and Damien Gruson. "Biotin interference: evaluation of a new generation of electrochemiluminescent immunoassays for high-sensitive troponin T and thyroid-stimulating hormone testing." Clinical Chemistry and Laboratory Medicine (CCLM) 58, no. 12 (November 26, 2020): 2037–45. http://dx.doi.org/10.1515/cclm-2020-0214.

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AbstractBackgroundBiotin is currently a matter of concern for laboratories using biotin-streptavidin-based immunoassays. Biotin interferences have been reported for high-sensitive troponin T (hsTnT) and thyroid-stimulating hormone (TSH) assays. We aimed to evaluate the new generation of hsTnT and TSH electrochemiluminescent immunoassays announced to be less sensitive to biotin.MethodsFirstly, we assessed the analytical performances of new generation assays (imprecision, bias, total error, limit of quantification) and compared previous and new generation assays in the absence of biotin. Secondly, we challenged both generations of assays with samples spiked with seven different biotin levels. The efficiency of new generation assays was also compared to the streptavidin beads treatment.ResultsNew generation assays presented suitable analytical performances. Previous and new generations of hsTnT and TSH assays were commutable in the absence of biotin. In the presence of biotin, we confirmed that previous generation assays were affected by biotin concentration as low as 40.5 ng/mL and that new generation assays were not affected up to the announced tolerance threshold of 1200 ng/mL. After the streptavidin beads treatment, we observed a higher imprecision for both parameters and a constant 10% negative bias for TSH compared to new generation assays.ConclusionsNew generation of electrochemiluminescent immunoassays appears as a reliable systematic solution to prevent biotin interference for hsTnT and TSH testing.

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SCHNYDER, Anita, Stefan KRÄHENBÜHL, Michael TÖRÖK, Jürgen DREWE, and Jörg HUWYLER. "Targeting of skeletal muscle in vitro using biotinylated immunoliposomes." Biochemical Journal 377, no. 1 (January 1, 2004): 61–67. http://dx.doi.org/10.1042/bj20031034.

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In the present study, a non-covalent (biotin–streptavidin) coupling procedure for the preparation of pegylated immunoliposomes is presented, which simplifies the attachment of targeting vectors to sterically stabilized liposomes. A biotinylated poly(ethylene glycol) (PEG)-phospholipid [bio-PEG-distearoylphosphatidylethanolamine (DSPE)] was used as a linker between a streptavidin-conjugated monoclonal antibody (mAb) (i.e. the OX26 mAb raised against the rat transferrin receptor) and 150 nm liposomes. OX26–streptavidin had a biotin binding capacity of two to three biotin molecules per OX26–streptavidin conjugate. Immunostaining experiments with the OX26 mAb followed by fluorescent confocal microscopy revealed immunofluorescence labelling of the transferrin receptor on skeletal muscle, as well as in L6 cells, a continuous cell line derived from rat skeletal muscle. Uptake experiments with L6 cells using the OX26 mAb, fluorescence-labelled OX26–streptavidin or fluorescent OX26-immunoliposomes demonstrated cellular uptake and accumulation within an intracellular compartment of the OX26 mAb and its conjugates. Cellular uptake of OX26 conjugates was sensitive to competition with free OX26 antibody. In summary, these studies describe the design of biotinylated immunoliposomes as a universal drug transport vector and their potential for targeting of the transferrin receptor of skeletal muscle.

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Schendel, Leonard C., Steffen M. Sedlak, and Hermann E. Gaub. "Switchable reinforced streptavidin." Nanoscale 12, no. 12 (2020): 6803–9. http://dx.doi.org/10.1039/d0nr00265h.

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Frame, Ithiel J., Parag H. Joshi, Caroline Mwangi, Ian Gunsolus, James A. De Lemos, Sandeep R. Das, Ravi Sarode, Jyoti Balani, Fred S. Apple, and Alagarraju Muthukumar. "Susceptibility of Cardiac Troponin Assays to Biotin Interference." American Journal of Clinical Pathology 151, no. 5 (February 2, 2019): 486–93. http://dx.doi.org/10.1093/ajcp/aqy172.

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Abstract Objectives To investigate biotin interference on three cardiac troponin (cTn) assays and demonstrate a method to overcome biotin interference. Methods cTn levels were measured in (1) plasma from healthy volunteers on 10-mg daily biotin supplementation mixed with a plasma with known elevated troponin, (2) plasmas with known elevated cTn after mixing in reagent biotin to simulate supplementation, and (3) biotin-spiked plasma specimens pretreated with streptavidin-agarose beads. Results Daily biotin ingestion (10 mg) and studies simulating daily biotin use resulted in significant interference in the Gen5 cardiac troponin T (cTnT) assay; the contemporary Gen 4 cTnT and high-sensitivity cardiac troponin I (hs-cTnI) assays were unaffected. The biotin interference threshold was 31, 315, and more than 2,000 ng/mL for Gen5 cTnT, cTnT, and hs-cTnI assays, respectively. Streptavidin pretreatment blocked biotin interference in cTn assays. Conclusions Biotin interference is possible at plasma concentrations achievable by ingestion of over-the-counter supplements that may lead to delayed or missed diagnosis of myocardial injury with the Gen5 cTnT assay.

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Liao, Renjie, Thai Pham, Diego Mastroeni, Paul D. Coleman, Joshua Labaer, and Jia Guo. "Highly Sensitive and Multiplexed In-Situ Protein Profiling with Cleavable Fluorescent Streptavidin." Cells 9, no. 4 (April 1, 2020): 852. http://dx.doi.org/10.3390/cells9040852.

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The ability to perform highly sensitive and multiplexed in-situ protein analysis is crucial to advance our understanding of normal physiology and disease pathogenesis. To achieve this goal, we here develop an approach using cleavable biotin-conjugated antibodies and cleavable fluorescent streptavidin (CFS). In this approach, protein targets are first recognized by the cleavable biotin-labeled antibodies. Subsequently, CFS is applied to stain the protein targets. Though layer-by-layer signal amplification using cleavable biotin-conjugated orthogonal antibodies and CSF, the protein detection sensitivity can be enhanced at least 10-fold, compared with the current in-situ proteomics methods. After imaging, the fluorophore and the biotin unbound to streptavidin are removed by chemical cleavage. The leftover streptavidin is blocked by biotin. Upon reiterative analysis cycles, a large number of different proteins with a wide range of expression levels can be profiled in individual cells at the optical resolution. Applying this approach, we have demonstrated that multiple proteins are unambiguously detected in the same set of cells, regardless of the protein analysis order. We have also shown that this method can be successfully applied to quantify proteins in formalin-fixed paraffin-embedded (FFPE) tissues.

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Koo, Kai, Peggy M. Foegeding, and Harold E. Swaisgood. "Development of a Streptavidin-Conjugated Single-Chain Antibody That Binds Bacillus cereusSpores." Applied and Environmental Microbiology 64, no. 7 (July 1, 1998): 2497–502. http://dx.doi.org/10.1128/aem.64.7.2497-2502.1998.

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ABSTRACT Control of microorganisms such as Bacillus cereusspores is critical to ensure the safety and a long shelf life of foods. A bifunctional single chain antibody has been developed for detection and binding of B. cereus T spores. The genes that encodeB. cereus T spore single-chain antibody and streptavidin were connected for use in immunoassays and immobilization of the recombinant antibodies. A truncated streptavidin, which is smaller than but has biotin binding ability similar to that of streptavidin, was used as the affinity domain because of its high and specific affinity with biotin. The fusion protein gene was expressed in Escherichia coli BL21 (DE3) with the T7 RNA polymerase-T7 promoter expression system. Immunoblotting revealed an antigen specificity similar to that of its parent native monoclonal antibody. The single-chain antibody-streptavidin fusion protein can be used in an immunoassay ofB. cereus spores by applying a biotinylated enzyme detection system. The recombinant antibodies were immobilized on biotinylated magnetic beads by taking advantage of the strong biotin-streptavidin affinity. Various liquids were artificially contaminated with 5 × 104 B. cereusspores per ml. Greater than 90% of the B. cereus spores in phosphate buffer or 37% of the spores in whole milk were tightly bound and removed from the liquid phase by the immunomagnetic beads.

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Bayer, E. A., H. Ben-Hur, Y. Hiller, and M. Wilchek. "Postsecretory modifications of streptavidin." Biochemical Journal 259, no. 2 (April 15, 1989): 369–76. http://dx.doi.org/10.1042/bj2590369.

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Streptavidin, an extracellular biotin-binding protein from Streptomyces avidinii, exhibits a multiplicity in its electrophoretic mobility pattern which depends both upon the conditions for growth of the bacterium and upon the protocol used in the purification of the protein. The observed structural heterogeneity appears to reflect the action of two types of postsecretory molecular events: proteolytic digestion of the intact Mr-18,000 subunit to a minimal molecular size (approx. Mr 14,000), and aggregation of the native tetramer into higher-order oligomeric forms. The extent of subunit degradation and/or tetrameric aggregation affects the capacity of a given streptavidin preparation to interact with biotin-conjugated proteins in different assay systems.

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Berghorn, K. A., J. H. Bonnett, and G. E. Hoffman. "cFos immunoreactivity is enhanced with biotin amplification." Journal of Histochemistry & Cytochemistry 42, no. 12 (December 1994): 1635–42. http://dx.doi.org/10.1177/42.12.7983364.

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Through modification of the protocol by Adams, we developed a biotin amplification procedure for immunofluorescence staining of immediate early gene proteins and also applied biotin amplification for metal enhancement of diaminobenzidine staining in an immunoperoxidase protocol. Commercially available anti-cFos antisera were used to compare conventional "Elite" avidin-biotin complex reactions with biotin amplification reactions (visualized with peroxidase staining or streptavidin-Texas Red fluorescence). Biotin amplification and peroxidase staining (with or without nickel salts) enabled detection of cFos in stimulated neurons with primary antibody concentrations five- to tenfold lower than the conventional procedure. With immunofluorescence staining, at primary antibody concentrations too low to detect cFos with the conventional biotin-streptavidin fluorescence staining protocol, biotin amplification enabled clear cFos fluorescence staining with both antisera. The fluorescence staining exhibited a high signal-to-noise ratio and enabled antibody concentrations four times lower than those used for conventional ABC "Elite" peroxidase procedures. In conclusion, the application of biotin amplification to cFos immunocytochemical localization has the promise of aiding the scientist in detecting these immediate early gene products.

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Dadfar, Seyed Mohammad Mahdi, Sylwia Sekula-Neuner, Vanessa Trouillet, Hui-Yu Liu, Ravi Kumar, Annie K. Powell, and Michael Hirtz. "Evaluation of click chemistry microarrays for immunosensing of alpha-fetoprotein (AFP)." Beilstein Journal of Nanotechnology 10 (December 16, 2019): 2505–15. http://dx.doi.org/10.3762/bjnano.10.241.

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The level of cancer biomarkers in cells, tissues or body fluids can be used for the prediction of the presence of cancer or can even indicate the stage of the disease. Alpha-fetoprotein (AFP) is the most commonly used biomarker for early screening and diagnosis of hepatocellular carcinoma (HCC). Here, a combination of three techniques (click chemistry, the biotin–streptavidin–biotin sandwich strategy and the use of antigen–antibody interactions) were combined to implement a sensitive fluorescent immunosensor for AFP detection. Three types of functionalized glasses (dibenzocyclooctyne- (DBCO-), thiol- and epoxy-terminated surfaces) were biotinylated by employing the respective adequate click chemistry counterparts (biotin–thiol or biotin–azide for the first class, biotin–maleimide or biotin–DBCO for the second class and biotin–amine or biotin–thiol for the third class). The anti-AFP antibody was immobilized on the surfaces via a biotin–streptavidin–biotin sandwich technique. To evaluate the sensing performance of the differently prepared surfaces, fluorescently labeled AFP was spotted onto them via microchannel cantilever spotting (µCS). Based on the fluorescence measurements, the optimal microarray design was found and its sensitivity was determined.

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Santi, Nicolò, Louis C. Morrill, and Louis Y. P. Luk. "Streptavidin-Hosted Organocatalytic Aldol Addition." Molecules 25, no. 10 (May 25, 2020): 2457. http://dx.doi.org/10.3390/molecules25102457.

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In this report, the streptavidin-biotin technology was applied to enable organocatalytic aldol addition. By attaching pyrrolidine to the valeric motif of biotin and introducing it to streptavidin (Sav), a protein-based organocatalytic system was created, and the aldol addition of acetone with p-nitrobenzaldehyde was tested. The conversion of substrate to product can be as high as 93%. Although the observed enantioselectivity was only moderate (33:67 er), further protein engineering efforts can be included to improve the selectivity. These results have proven the concept that Sav can be used to host stereoselective aldol addition.

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Sedlak, Steffen M., Leonard C. Schendel, Hermann E. Gaub, and Rafael C. Bernardi. "Streptavidin/biotin: Tethering geometry defines unbinding mechanics." Science Advances 6, no. 13 (March 2020): eaay5999. http://dx.doi.org/10.1126/sciadv.aay5999.

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Macromolecules tend to respond to applied forces in many different ways. Chemistry at high shear forces can be intriguing, with relatively soft bonds becoming very stiff in specific force-loading geometries. Largely used in bionanotechnology, an important case is the streptavidin (SA)/biotin interaction. Although SA’s four subunits have the same affinity, we find that the forces required to break the SA/biotin bond depend strongly on the attachment geometry. With AFM-based single-molecule force spectroscopy (SMFS), we measured unbinding forces of biotin from different SA subunits to range from 100 to more than 400 pN. Using a wide-sampling approach, we carried out hundreds of all-atom steered molecular dynamics (SMD) simulations for the entire system, including molecular linkers. Our strategy revealed the molecular mechanism that causes a fourfold difference in mechanical stability: Certain force-loading geometries induce conformational changes in SA’s binding pocket lowering the energy barrier, which biotin has to overcome to escape the pocket.

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Khosravi, M. J., and R. C. Morton. "Novel application of streptavidin-hapten derivatives as protein-tracer conjugate in competitive-type immunoassays involving biotinylated detection probes." Clinical Chemistry 37, no. 1 (January 1, 1991): 58–63. http://dx.doi.org/10.1093/clinchem/37.1.58.

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Abstract To investigate the use of streptavidin-hapten derivatives as potential protein-tracer conjugates for competitive-type immunoassays, we labeled streptavidin with cortisol and compared biotin-binding activity of the conjugates with that of unlabeled streptavidin. In this model system, streptavidin labeled with one to approximately 17 cortisol molecules retained its capability to cross-link a biotinylated protein on microtiter wells to a biotin-based general detection reagent developed for time-resolved fluorometry. Compared with unlabeled streptavidin, there was no reduction in the binding activity of the conjugate carrying as many as 2.6 cortisol molecules per molecule of streptavidin. Conjugation ratios greater than 4.4 showed a slight decrease in binding activity, presumably because of the aggregate formation evident at these labeling ratios. As expected, the conjugates were also capable of linking a solid-phase-bound anti-cortisol monoclonal antibody to the biotinylated detection reagent. The fluorescence signal generated increased almost linearly with increasing conjugation ratios from about three to nine cortisol molecules per molecule of streptavidin. At greater ratios, the assay response plateaued. The calibration curves obtained were typical for competitive-type immunoassays when the conjugates were incorporated in a cortisol assay based on a second-antibody immobilization approach.

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Hamblett, Kevin J., Brian B. Kegley, Don K. Hamlin, Ming-Kuan Chyan, David E. Hyre, Oliver W. Press, D. Scott Wilbur, and Patrick S. Stayton. "A Streptavidin−Biotin Binding System That Minimizes Blocking by Endogenous Biotin." Bioconjugate Chemistry 13, no. 3 (May 2002): 588–98. http://dx.doi.org/10.1021/bc010087t.

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Waner, Mark J., and David P. Mascotti. "A simple spectrophotometric streptavidin–biotin binding assay utilizing biotin-4-fluorescein." Journal of Biochemical and Biophysical Methods 70, no. 6 (April 2008): 873–77. http://dx.doi.org/10.1016/j.jbbm.2007.06.001.

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Niether, Doreen, Mona Sarter, Bernd W. Koenig, Jörg Fitter, Andreas M. Stadler, and Simone Wiegand. "Thermophoresis: The Case of Streptavidin and Biotin." Polymers 12, no. 2 (February 7, 2020): 376. http://dx.doi.org/10.3390/polym12020376.

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Thermophoretic behavior of a free protein changes upon ligand binding and gives access to information on the binding constants. The Soret effect has also been proven to be a promising tool to gain information on the hydration layer, as the temperature dependence of the thermodiffusion behavior is sensitive to solute–solvent interactions. In this work, we perform systematic thermophoretic measurements of the protein streptavidin (STV) and of the complex STV with biotin (B) using thermal diffusion forced Rayleigh scattering (TDFRS). Our experiments show that the temperature sensitivity of the Soret coefficient is reduced for the complex compared to the free protein. We discuss our data in comparison with recent quasi-elastic neutron scattering (QENS) measurements. As the QENS measurement has been performed in heavy water, we perform additional measurements in water/heavy water mixtures. Finally, we also elucidate the challenges arising from the quantiative thermophoretic study of complex multicomponent systems such as protein solutions.

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Jones, M. Lisa, and Gary P. Kurzban. "Noncooperativity of Biotin Binding to Tetrameric Streptavidin." Biochemistry 34, no. 37 (September 19, 1995): 11750–56. http://dx.doi.org/10.1021/bi00037a012.

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Wu, Yung-Peng, Chee Ying Chew, Tian-Neng Li, Tzu-Hsuan Chung, En-Hao Chang, Chak Hin Lam, and Kui-Thong Tan. "Target-activated streptavidin–biotin controlled binding probe." Chemical Science 9, no. 3 (2018): 770–76. http://dx.doi.org/10.1039/c7sc04014h.

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The streptavidin–biotin controlled binding probe has several advantages for the detection of enzymes and reactive small molecules, such as minimal background, multiple signal amplification steps, and wide selection of the optimal dyes for detection.

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Galarreta, Betty C., Peter R. Norton, and François Lagugné-Labarthet. "SERS Detection of Streptavidin/Biotin Monolayer Assemblies†." Langmuir 27, no. 4 (February 15, 2011): 1494–98. http://dx.doi.org/10.1021/la1047497.

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38

Xu, Dongdong, and Seraphine V. Wegner. "Multifunctional streptavidin–biotin conjugates with precise stoichiometries." Chemical Science 11, no. 17 (2020): 4422–29. http://dx.doi.org/10.1039/d0sc01589j.

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Multifunctional streptavidin-biotin conjugates with defined stoichiometry and number of open binding pockets provide molecularly precise alternatives to the statistical mixture of products that typically forms.

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Yang, Haoyue, and Toshiya Sakata. "Molecular-Charge-Contact-Based Ion-Sensitive Field-Effect Transistor Sensor in Microfluidic System for Protein Sensing." Sensors 19, no. 15 (August 2, 2019): 3393. http://dx.doi.org/10.3390/s19153393.

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In this paper, we demonstrate the possibility of direct protein sensing beyond the Debye length limit using a molecular-charge-contact (MCC)-based ion-sensitive field-effect transistor (ISFET) sensor combined with a microfluidic device. Different from the MCC method previously reported, biotin-coated magnetic beads are set on the gate insulator of an ISFET using a button magnet before the injection of target molecules such as streptavidin. Then, the streptavidin—a biotin interaction, used as a model of antigen—antibody reaction is expected at the magnetic beads/gate insulator nanogap interface, changing the pH at the solution/dielectric interface owing to the weak acidity of streptavidin. In addition, the effect of the pH or ionic strength of the measurement solutions on the electrical signals of the MCC-based ISFET sensor is investigated. Furthermore, bound/free (B/F) molecule separation with a microfluidic device is very important to obtain an actual electrical signal based on the streptavidin–biotin interaction. Platforms based on the MCC method are suitable for exploiting the advantages of ISFETs as pH sensors, that is, direct monitoring systems for antigen–antibody reactions in the field of in vitro diagnostics.

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Qiu, X. Q., K. S. Jakes, P. K. Kienker, A. Finkelstein, and S. L. Slatin. "Major transmembrane movement associated with colicin Ia channel gating." Journal of General Physiology 107, no. 3 (March 1, 1996): 313–28. http://dx.doi.org/10.1085/jgp.107.3.313.

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Colicin Ia, a bacterial protein toxin of 626 amino acid residues, forms voltage-dependent channels in planar lipid bilayer membranes. We have exploited the high affinity binding of streptavidin to biotin to map the topology of the channel-forming domain (roughly 175 residues of the COOH-terminal end) with respect to the membrane. That is, we have determined, for the channel's open and closed states, which parts of this domain are exposed to the aqueous solutions on either side of the membrane and which are inserted into the bilayer. This was done by biotinylating cysteine residues introduced by site-directed mutagenesis, and monitoring by electrophysiological methods the effect of streptavidin addition on channel behavior. We have identified a region of at least 68 residues that flips back and forth across the membrane in association with channel opening and closing. This identification was based on our observations that for mutants biotinylated in this region, streptavidin added to the cis (colicin-containing) compartment interfered with channel opening, and trans streptavidin interfered with channel closing. (If biotin was linked to the colicin by a disulfide bond, the effects of streptavidin on channel closing could be reversed by detaching the streptavidin-biotin complex from the colicin, using a water-soluble reducing agent. This showed that the cysteine sulfur, not just the biotin, is exposed to the trans solution). The upstream and downstream segments flanking the translocated region move into and out of the bilayer during channel opening and closing, forming two transmembrane segments. Surprisingly, if any of several residues near the upstream end of the translocated region is held on the cis side by streptavidin, the colicin still forms voltage-dependent channels, indicating that a part of the protein that normally is fully translocated across the membrane can become the upstream transmembrane segment. Evidently, the identity of the upstream transmembrane segment is not crucial to channel formation, and several open channel structures can exist.

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Avery, Gordon. "Biotin interference in immunoassay: a review for the laboratory scientist." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 56, no. 4 (April 25, 2019): 424–30. http://dx.doi.org/10.1177/0004563219842231.

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The recent FDA Biotin (Vitamin B7): Safety Communication – May Interfere with Lab Tests and A statement from the ACB Scientific Committee regarding biotin/vitamin B7 interference in immunoassays have raised into the laboratory consciousness the need to understand and to manage the issues around biotin interference with some immunoassays and to provide education and advice to health-care providers. In patients who are prescribed biotin or take biotin supplements, biotin has the potential to cause falsely low or falsely high results in immunoassays using streptavidin–biotin binding as part of the assay methodology. Streptavidin–biotin binding is used by many manufacturers; some manufacturers use it for most of their immunoassays, some for a few of their immunoassays and some manufacturers do not use this assay format at all. The direction and magnitude of interference and the concentration of biotin which affects an assay are highly variable and assay specific. There have been many papers and case reports published recently of biotin interference in immunoassay, and biotin interference is probably one of the most difficult types of inference to detect and to obviate. This review will assess the currently available information on this topic and review the steps the laboratory can take to reduce the risk of incorrect patient results being reported.

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Freitag, Stefanie, Isolde Le Trong, Lisa A. Klumb, Patrick S. Stayton, and Ronald E. Stenkamp. "Atomic resolution structure of biotin-free Tyr43Phe streptavidin: what is in the binding site?" Acta Crystallographica Section D Biological Crystallography 55, no. 6 (June 1, 1999): 1118–26. http://dx.doi.org/10.1107/s0907444999002322.

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The streptavidin–biotin system is an example of a high-affinity protein–ligand pair (Ka ≃ 1013 mol−1). The thermodynamic and structural properties have been extensively studied as a model system for protein–ligand interactions. Here, the X-ray crystal structure of a streptavidin mutant of a residue hydrogen bonding to biotin [Tyr43Phe (Y43F)] is reported at atomic resolution (1.14 Å). The biotin-free structure was refined with anisotropic displacement parameters (using the SHELXL97 program package). The high-resolution data also allowed interpretation of side-chain and residue disorder in 41 residues where alternate conformations were refined. The Y43F mutation is unambiguously observed in difference maps, although only a single O atom per monomer is altered. The atomic resolution enabled the identification of 2-methyl-2,4-pentanediol (MPD) molecules in the biotin-binding pocket for the first time. Electron density for MPD was observed in all four subunit binding sites of the tetrameric protein. This was not possible with data at lower resolution (1.8–2.3 Å) for wild-type streptavidin or mutants in the same crystal form using MPD in the crystallization. The impact of MPD binding on these studies is discussed.

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Chang, Yaw Jen. "Patterned ZnO Nanowires between Interdigitated Electrodes by Integrating Hydrothermal Approach with Photolithography Process." Materials Science Forum 990 (May 2020): 283–87. http://dx.doi.org/10.4028/www.scientific.net/msf.990.283.

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This paper presents a simple approach to selectively synthesize the ZnO nanowires between interdigitated electrodes by integrating the hydrothermal method with the photolithography process. The printed circuit board (PCB) was adopted as the substrate. Interdigitated electrodes were fabricated by etching the copper foil of PCB. Then, both the positive and negative photoresists were used to control the growth of nanowires through lift-off concept. No costly materials and expensive apparatuses are required. Biotin–streptavidin reaction was used as an example to examine this proposed device. When histidine-tagged biotin was added and the reaction of biotin–streptavidin was completed, the distinguishable I-V curves were detected, respectively. The experimental results reveal that this proposed device is sensitive.

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Saha, Sounik, Ritankar Majumdar, Akhtar Hussain, Rajan R. Dighe, and Akhil R. Chakravarty. "Biotin-conjugated tumour-targeting photocytotoxic iron(III) complexes." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, no. 1995 (July 28, 2013): 20120190. http://dx.doi.org/10.1098/rsta.2012.0190.

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Iron(III) complexes [FeL(B)] ( 1 – 4 ) of a tetradentate phenolate-based ligand (H 3 L) and biotin-conjugated dipyridophenazine bases (B), viz. 7-aminodipyrido [3,2- a :2′,3′- c ]-phenazine (dppza in 1 ), ( N -dipyrido[3,2- a :2′,3′- c ]-phenazino)amidobiotin (dppzNB in 2 ), dipyrido [3,2- a :2′,3′- c ]-phenazine-11-carboxylic acid (dppzc in 3 ) and 2-((2-biotinamido)ethyl) amido-dipyrido[3,2- a :2′,3′- c ]-phenazine (dppzCB in 4 ) are prepared, characterized and their interaction with streptavidin and DNA and their photocytotoxicity and cellular uptake in various cells studied. The high-spin iron(III) complexes display Fe(III)/Fe(II) redox couple near −0.7 V versus saturated calomel electrode in dimethyl sulfoxide–0.1 M tetrabutylammonium perchlorate. The complexes show non-specific interaction with DNA as determined from the binding studies. Complexes with appended biotin moiety show similar binding to streptavidin as that of free biotin, suggesting biotin conjugation to dppz does not cause any loss in its binding affinity to streptavidin. The photocytotoxicity of the complexes is tested in HepG2, HeLa and HEK293 cell lines. Complex 2 shows higher photocytotoxicity in HepG2 cells than in HeLa or HEK293, forming reactive oxygen species. This effect is attributed to the presence of overexpressed sodium-dependent multi-vitamin transporters in HepG2 cells. Microscopic studies in HepG2 cells show internalization of the biotin complexes 2 and 4 essentially occurring by receptor-mediated endocytosis, which is similar to that of native biotin and biotin fluorescein isothiocyanate conjugate.

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Moore, Nathan W., Anthony R. C. Delacruz, Katherine S. Lancaster, Thorsten Dieckmann, and Tonya L. Kuhl. "Synthesis of a Reversible Streptavidin Binder for Biomimetic Assemblies." Australian Journal of Chemistry 60, no. 5 (2007): 363. http://dx.doi.org/10.1071/ch06319.

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The biotin/streptavidin ligand/receptor pair is used extensively in biotechnology. However, less is known about HABA (2-(4-hydroxyphenylazo)benzoic acid), which binds to streptavidin with a bond energy and dissociation constant that more closely mimics antibody/antigen interactions. In this work we demonstrate some of HABA’s useful properties that may make it a good substitute for biotin in a broad range of biochemical research. Specifically, we investigate its ease of conjugation to an anchoring pegylated lipid, characterization with MALDI, NMR, and visible-wavelength spectroscopies, and incorporation into lipid vesicles.

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Ying, Le, Nuli Xie, Yanjing Yang, Xiaohai Yang, Qifeng Zhou, Bincheng Yin, Jin Huang, and Kemin Wang. "A cell-surface-anchored ratiometric i-motif sensor for extracellular pH detection." Chemical Communications 52, no. 50 (2016): 7818–21. http://dx.doi.org/10.1039/c6cc03163c.

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47

Ahlers, M., S. A. Darst, D. W. Grainger, R. D. Kornberg, W. Müller, A. Reichert, H. Ringsdorf, E. Rump, and C. Salesse. "Interaction of Proteins with Functional Monolayers: Recognition, 2D-Crystallization and Function." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 608–9. http://dx.doi.org/10.1017/s0424820100181804.

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The interaction of molecular self organization and molecular recognition leads to the formation of functional supramolecular systems (see Figure 1). They combine order and mobility and their function is based on their organization.’ These fascinating phenomena - and the living cell is only the most perfect example - can help to mimic biomembrane processes as well as to develop new materials. The interaction of proteins with biomembranes is of fundamental relevance in many fields of biochemistry and medicine. Model biomembranes offer the possibility to simulate such naturally occuring processes. The monolayer technique in particular has proven to be an ideal tool to investigate the interaction of water soluble proteins with model membranes. Unspecific adsorption of proteins at charged lipid monolayers, specific recognition of ligand molecules by proteins and enzyme binding followed by enzyme action may lead to highly oriented protein domains and even to 2D-crystallization (see Figure 2).Due to its high binding constant (Kd = 10−15 mol-1), the biotin/streptavidin system is an ideal tool to investigate the specific interaction between a membrane incorporated receptor and a protein. Streptavidin is a protein which comprises four identical subunits, each binding one biotin molecule, and is well known from affinity chromatography. Biotin lipids with biotinylated headgroups have been synthesized to act as the membrane-incorporated receptors. Injection of fluorescent-labeled streptavidin underneath a monolayer of biotin lipids in the gas-analogue state results in formation of regular H-shaped optically anisotropic two-dimensional streptavidin domains. The crystallinity of these two-dimensional domains was determined by electron crystallography, revealing diffraction patterns with a resolution of 1.5 nm. The match of the electron density map thus obtained and the X-ray crystal structure of streptavidin is remarkably close, showing that two binding sites are still free and face away from the lipid layer, exposed to the aqueous solution. This offers the possibility of building up protein multilayer structures - even a second crystalline protein layer is imaginable, using the first streptavidin layer as a matrix for the binding of other biotinylated proteins.

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Mondarte, Evan Angelo, Tatsuhiro Maekawa, Takashi Nyu, Hiroyuki Tahara, Ganchimeg Lkhamsuren, and Tomohiro Hayashi. "Detection of streptavidin–biotin intermediate metastable states at the single-molecule level using high temporal-resolution atomic force microscopy." RSC Advances 9, no. 39 (2019): 22705–12. http://dx.doi.org/10.1039/c9ra04106k.

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Han, Dong, Baolin Zhang, Chuangang Chong, Cuiping Rong, Jie Tan, and Rusen Yang. "A strategy for iron oxide nanoparticles to adhere to the neuronal membrane in the substantia nigra of mice." Journal of Materials Chemistry B 8, no. 4 (2020): 758–66. http://dx.doi.org/10.1039/c9tb02066g.

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Udompholkul, Parima, Carlo Baggio, Luca Gambini, Yu Sun, Ming Zhao, Robert M. Hoffman, and Maurizio Pellecchia. "Effective Tumor Targeting by EphA2-Agonist-Biotin-Streptavidin Conjugates." Molecules 26, no. 12 (June 17, 2021): 3687. http://dx.doi.org/10.3390/molecules26123687.

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We recently reported on a potent synthetic agent, 135H11, that selectively targets the receptor tyrosine kinase, EphA2. While 135H11 possesses a relatively high binding affinity for the ligand-binding domain of EphA2 (Kd~130 nM), receptor activation in the cell required the synthesis of dimeric versions of such agent (namely 135H12). This was expected given that the natural ephrin ligands also need to be dimerized or clustered to elicit agonistic activity in cell. In the present report we investigated whether the agonistic activity of 135H11 could be enhanced by biotin conjugation followed by complex formation with streptavidin. Therefore, we measured the agonistic EphA2 activity of 135H11-biotin (147B5) at various agent/streptavidin ratios, side by side with 135H12, and a scrambled version of 147B5 in pancreatic- and breast-cancer cell lines. The (147B5)n-streptavidin complexes (when n = 2, 3, 4, but not when n = 1) induced a strong receptor degradation effect in both cell lines compared to 135H12 or the (scrambled-147B5)4-streptavidin complex as a control, indicating that multimerization of the targeting agent resulted in an increased ability to cause receptor clustering and internalization. Subsequently, we prepared an Alexa-Fluor-streptavidin conjugate to demonstrate that (147B5)4-AF-streptavidin, but not the scrambled equivalent complex, concentrates in pancreatic and breast cancers in orthotopic nude-mouse models. Hence, we conclude that these novel targeting agents, with proper derivatization with imaging reagents or chemotherapy, can be used as diagnostics, and/or to deliver chemotherapy selectively to EphA2-expressing tumors.

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Journal articles on the topic 'Biotin-Streptavidin'

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