Journal articles: 'Affinity 2.0'

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Lepetit, Christine, Mogens Brøndsted Nielsen, François Diederich, and Remi Chauvin. "Aromaticity and Electron Affinity of Carbok-[3]radialenes,k=0, 1, 2." Chemistry - A European Journal 9, no. 20 (October 17, 2003): 5056–66. http://dx.doi.org/10.1002/chem.200305070.

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Beattie, J. M. A., J. P. Goss, M. J. Rayson, and P. R. Briddon. "Structure and electron affinity of silicon and germanium terminated (0 0 1)-(2 × 1) diamond surface." Journal of Physics: Condensed Matter 31, no. 39 (July 9, 2019): 395001. http://dx.doi.org/10.1088/1361-648x/ab2d6c.

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Breier, B. H., P. D. Gluckman, H. T. Blair, and S. N. McCutcheon. "Somatotrophic receptors in hepatic tissue of the developing male pig." Journal of Endocrinology 123, no. 1 (October 1989): 25–31. http://dx.doi.org/10.1677/joe.0.1230025.

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ABSTRACT The development of hepatic somatotrophic receptors and plasma concentrations of insulin-like growth factor-I (IGF-I) were investigated at five different ages (2, 20, 35, 105 and 165 days) in four male pigs per group. The specific binding of 125I-labelled porcine GH (pGH) to hepatic somatotrophic membranes was very low at 2 days of age (0·53±0·12%), and increased progressively (P <0·01) with advancing age to 3·60 ± 0·95% at 165 days of age. Specific binding of 125I-labelled bovine GH (bGH) to the same membrane preparations was markedly higher than binding of 125I-labelled pGH; it also showed a distinct developmental increase (P <0·01) with age from 4·4 ± 0·55% at 2 days of age to 24·0±1·90% at 165 days of age. Plasma concentrations of IGF-I increased significantly (P <0·01) from 79 ± 14·0 μg/l at 2 days of age to 610 ± 64·0 μg/l at 165 days of age. Non-linear regression analysis of the competitive binding data using bGH as labelled and unlabelled ligands showed linear Scatchard plots in the three youngest age groups, with an association constant (Ka) of approximately 3·5 litres/nmol. Curvilinear Scatchard plots were observed in the two oldest age groups. The Ka for the higher affinity binding site (approximately 5·0 litres/nmol) was very similar to that for the sole site observed in the younger animals. The Ka of the lower affinity binding site was approximately 0·35 litres/nmol. There was a significant (P <0·01) developmental increase in the capacity of the higher affinity binding site from 12 ± 4·6 pmol/100 mg liver at 2 days of age to 91 ± 23·0 pmol/100 mg liver at 165 days of age. These studies demonstrate heterogeneity of somatotrophic hepatic membranes in the pig and show that low concentrations of a high affinity binding site are already present in newborn pigs. A considerable developmental increase was observed in the capacity of this binding site which correlated significantly (r = 0·82, P <0·01, n = 20) with plasma concentrations of IGF-I. The role of the lower affinity binding site which was observed in addition to the high affinity binding site in older pigs is less clear. The data from the present study support the hypothesis that the postnatal rise in plasma concentrations of IGF-I is associated with the developmental increase of the capacity of the high affinity somatotrophic receptors. Journal of Endocrinology (1989) 123, 25–31

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John, W. G., and A. E. Jones. "Affinity Chromatography: A Precise Method for Glycosylated Albumin Estimation." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 22, no. 1 (January 1985): 79–83. http://dx.doi.org/10.1177/000456328502200108.

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A method is described for the estimation, in plasma, of glycosylated albumin, using the commercially available affinity chromatographic material Glycogel B (immobilised m-aminophenylboronic acid on an agarose support) to separate the glycosylated and non-glycosylated albumin, followed by the analysis of albumin concentration using rocket Immunoelectrophoresis. Glycosylated albumin and glycosylated haemoglobin showed good correlation (r=0·91) when both are estimated by affinity chromatography. The glycosylated albumin method displays good within-batch (2·8–4·4% CV) and between-batch (2·9–5·4% CV) precision, and the method is not affected by haemolysis. Using this method a reference range of 2·0–5·4% was found for glycosylated albumin. Levels of glycosylated albumin in diabetics (10·06±3·23%) were found to be significantly higher ( P<0·001) than those in non-diabetics (3·72±0·85%). It was found that loading more than 3 mg of albumin on to a 1 mL affinity column must be avoided, as this appears to overload the column.

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Janausch, Ingo G., Inma Garcia-Moreno, Daniela Lehnen, Yvonne Zeuner, and Gottfried Unden. "Phosphorylation and DNA binding of the regulator DcuR of the fumarate-responsive two-component system DcuSR of Escherichia coli." Microbiology 150, no. 4 (April 1, 2004): 877–83. http://dx.doi.org/10.1099/mic.0.26900-0.

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The function of the response regulator DcuR of the DcuSR fumarate two-component sensory system of Escherichia coli was analysed in vitro. Isolated DcuR protein was phosphorylated by the sensory histidine kinase, DcuS, and ATP, or by acetyl phosphate. In gel retardation assays with target promoters (frdA, dcuB, dctA), phosphoryl DcuR (DcuR-P) formed a high-affinity complex, with an apparent K D (app. K D) of 0·2–0·3 μM DcuR-P, and a low-affinity (app. K D 0·8–2 μM) complex. The high-affinity complex was formed only with promoters transcriptionally-regulated by DcuSR, whereas low-affinity binding was seen also with some DcuSR-independent promoters. The binding site of DcuR-P at the dcuB promoter was determined by DNase I footprinting. One binding site of 42–52 nt (position −359 to −400/−410 nt upstream of the transcriptional start) was identified in the presence of low and high concentrations of DcuR-P. Non-phosphorylated DcuR, or DcuR-D56N mutated in the phosphoryl-accepting Asp56 residue, showed low-affinity binding to target promoters. DcuR-D56N was still able to interact with DcuS. DcuR-D56N increased the phosphorylation of DcuS and competitively inhibited phosphoryl transfer to wild-type DcuR.

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BEDURFTIG, S. "Chiral, nonracemic (piperazin-2-yl)methanol derivatives with $sigma;-receptor affinity." Bioorganic & Medicinal Chemistry 12, no. 12 (June 2004): 3299–311. http://dx.doi.org/10.1016/s0968-0896(04)00264-0.

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7

Breier, B. H., P. D. Gluckman, and J. J. Bass. "The somatotrophic axis in young steers: influence of nutritional status and oestradiol-17β on hepatic high-and low-affinity somatotrophic binding sites." Journal of Endocrinology 116, no. 2 (February 1988): 169–77. http://dx.doi.org/10.1677/joe.0.1160169.

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ABSTRACT The binding of bovine GH (bGH) to hepatic membranes obtained from steers on either high (3% dry matter of body weight per day) or low (1% dry matter of body weight per day) planes of nutrition with or without an oestradiol-17β implant was studied (n = 5 per group). Binding studies were performed on both crude membrane homogenates and on 100 000 g microsomal membrane fractions; identical results were obtained using both preparations. In all four groups of animals, linear Scatchard plots were obtained, but following pretreatment of the membranes with MgCl2 to remove endogenously bound hormone, curvilinear plots were obtained in the groups on the high plane of nutrition. Analysis of these curves suggested the presence of a high- and low-affinity binding site, the high-affinity site being fully occupied in the absence of MgCl2 pretreatment. The specific binding of bGH in MgCl2-pretreated crude membranes was greater (P < 0·01) in well-fed steers (14·8 ± 1·6%) than in poorly fed steers (9·8 ± 0·9%). Scatchard analysis showed this to be due to the presence of a high-affinity site (dissociation constant (Kd) = 11·6 ± 3·3 pmol/l) in the well-fed animals only. In addition, there was an increase (P < 0·01) in the affinity, but not in the capacity, of the low-affinity site (Kd = 106·4 ± 22·8 pmol/l in well-fed steers and 197·0 ± 23·8 pmol/l in poorly fed steers). Oestradiol treatment was associated with an increase (P < 0·01) in specific binding at both planes of nutrition, but binding was higher (P < 0·01) in well-fed (24·8 ± 2·9%) than in poorly fed (15·6 ± 3·7%) steers. Scatchard analysis after MgCl2 pretreatment again showed a curvilinear plot at the high and a linear plot at the low nutritional plane. The effect of oestradiol was to increase (P < 0·001) the capacity of the high-affinity site from 1·87 ± 0·61 pmol/100 mg in the control well-fed group to 6·56 ± 1 ·2 pmol/100 mg. The capacity of the low-affinity site was increased (P < 0·01) from 20·1 ± 2·6 to 30·1 ± 3·2 pmol/100 mg in the well-fed group, with a similar change in the poorly fed group. Oestradiol had no effect on the apparent affinity of either binding site. These studies demonstrate a heterogeneity of somatotrophic binding sites of hepatic membranes in steers. The presence of a high-affinity site is determined by nutritional status, whereas oestradiol primarily affects receptor capacity. Thus nutrition and oestradiol have independent and qualitatively different effects on somatotrophic binding. As the rate of weight gain correlated (P < 0·01) with the capacity of the high-affinity site, it is suggested that somatotrophic receptor modulation is a primary factor in the regulation of somatic growth in the ruminant. J. Endocr. (1988) 116, 169–177

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McGrattan, P. D., A. R. G. Wylie, and J. Nelson. "Tissue-specific differences in insulin binding affinity and insulin receptor concentrations in skeletal muscles, adipose tissue depots and liver of cattle and sheep." Animal Science 71, no. 3 (December 2000): 501–8. http://dx.doi.org/10.1017/s1357729800055466.

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AbstractDifferences in insulin binding affinity and in concentrations of insulin receptor, were found in a variety of tissues taken, at slaughter, from mature steers (701 (s.d. 23) kg) and growing lambs (47 (s.d. 2·1) kg). In both species, liver had lower insulin binding affinity than skeletal muscles m. pectineus m. longissimus dorsi and m. rectus capitis (all P < 0·001) and subcutaneous, omental and perirenal adipose depots (all P < 0·001). Site-specific differences in affinity for insulin existed between adipose depots (subcutaneous < omental, P < 0·05; subcutaneous < perirenal, P < 0·001) and between tissue-types (subcutaneous fat < m. pectineus skeletal muscle, P < 0·05; m. rectus capitis < perirenal fat, P < 0·05) in steers. In lambs also, receptor affinity for insulin differed between tissue-type (m. longissimus dorsi < perirenal fat, P < 0·05; m. rectus capitis < subcutaneous fat, P < 0·05 and m. rectus capitis < perirenal fat, P < 0·001) but lambs did not show the adipose depot-specific differences in insulin affinity observed in steers. Insulin receptor concentration differed between adipose depots (subcutaneous < omental, P < 0·05; subcutaneous < perirenal, P < 0·01) and between tissue-type (m. pectineus < perirenal fat P < 0·05) in steers and perirenal and subcutaneous adipose depots of lambs had higher receptor concentrations than m. longissimus dorsi and m. pectineusP < 0·001). This is the first study to demonstrate, in any species, differences in insulin receptor binding affinity and receptor concentration in a wide range of tissues (liver, skeletal muscles and adipose depots) from the same individual. Such differences in meat-producing animals could, through effects on tissue sensitivity and/or responsiveness to insulin, influence nutrient partitioning to tissues and affect overall rates of lipid storage and net protein synthesis.

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Asai, Daisuke, Masaharu Murata, Riki Toita, Takahito Kawano, Hideki Nakashima, and Jeong-Hun Kang. "A high-affinity peptide substrate for G protein-coupled receptor kinase 2 (GRK2)." Amino Acids 51, no. 6 (April 19, 2019): 973–76. http://dx.doi.org/10.1007/s00726-019-02735-0.

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10

Sud’ina, A. E., T. S. Zatsepin, V. Pingoud, A. Pingoud, T. S. Oretskaya, and E. A. Kubareva. "Affinity Modification of the Restriction Endonuclease SsoII by 2′-Aldehyde-Containing Double Stranded DNAs." Biochemistry (Moscow) 70, no. 8 (August 2005): 941–47. http://dx.doi.org/10.1007/s10541-005-0206-0.

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11

Ellis, S. T., R. B. Heap, A. R. Butchart, V. Rider, N. E. Richardson, M. W. Wang, and M. J. Taussig. "Efficacy and specificity of monoclonal antibodies to progesterone in preventing the establishment of pregnancy in the mouse." Journal of Endocrinology 118, no. 1 (July 1988): 69–80. http://dx.doi.org/10.1677/joe.0.1180069.

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ABSTRACT Anti-progesterone monoclonal antibody prevents the establishment of pregnancy in BALB/c mice by the prevention of implantation when injected i.p. 32 h after mating. To determine the specificity of this effect, mice were injected with immune and non-immune purified mouse immunoglobulins. The results show that anti-implantation efficacy was due to high-affinity antibody which bound progesterone since two further mouse immunoglobulin (Ig) G1 preparations, mouse IgA and mouse IgM which failed to bind the steroid, had no effect on pregnancy rates. From a panel of anti-progesterone monoclonal antibodies, six with a high affinity (affinity constant, 0·24–0·80 litres/nmol) and specificity for progesterone were selected for additional studies. Anti-implantation efficacy for five antibodies was similar, with a 50% effective dose within the range of 0·8–2·0 nmol. Antibody reached high concentrations in plasma within 12 h after i.p. injection, and declined with a half-life of about 80 h. Purified F(ab′)2 fragments of antibody also bound progesterone, but were less effective than the native molecule in blocking pregnancy. The results show that implantation in the mouse can be blocked by a high-affinity antibody that binds progesterone and which is removed from the blood at a slow rate. J. Endocr. (1988) 118, 69–80

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Slootweg, M. C., J. P. Salles, C. Ohlsson, C. P. de Vries, M. J. E. Engelbregt, and J. C. Netelenbos. "Growth hormone binds to a single high affinity receptor site on mouse osteoblasts: modulation by retinoic acid and cell differentiation." Journal of Endocrinology 150, no. 3 (September 1996): 465–72. http://dx.doi.org/10.1677/joe.0.1500465.

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Abstract Growth hormone (GH) exerts direct differentiative and proliferative effects on osteoblasts. We studied 125I-labeled human (h) GH binding to primary mouse osteoblasts derived from collagenase-treated 18-day fetal mouse calvaria. Scatchard analysis of the data revealed a single class of high affinity GH receptors (apparent Ka= 5·74 × 109 m−1) with 2200 sites per cell. Affinity cross-linking and SDS-PAGE electrophoresis showed two bands with apparent molecular masses of 120 and 70 kDa. Mouse osteoblasts express GH receptor mRNA with gene transcripts of 4·2 and 1·2 kb, at levels which reach approximately 1/6 of those in mouse liver and 1/3 of those in mouse muscle. Two populations of undifferentiated and diffentiated osteoblasts, obtained by sequential collagenase digestion of mouse calvaria, were used to study the relationship between osteoblastic phenotype and GH receptor expression. Although the affinity of the receptors in undifferentiated and differentiated cells was the same, the capacity was significantly higher (1·45 ± 1·0% vs 2·39 ± 0·9%, P=0·03) in differentiated cells. This stresses the specific importance of the osteoblast as a target cell for GH. The differentiating potential of the vitamin A derivative retinoic acid was subsequently used experimentally to induce differentiation in the cells. Retinoic acid increased 125I-hGH binding to preosteoblasts (153%, P=0·02). Together, these data demonstrate the presence of a high affinity GH receptor in mouse osteoblasts which is related to differentiation. Journal of Endocrinology (1996) 150, 465–472

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Karwowski, Boleslaw. "Ionisation potential and electron affinity of free 5′,8-cyclopurine-2′-deoxynucleosides. DFT study in gaseous and aqueous phase." Open Chemistry 8, no. 1 (February 1, 2010): 70–76. http://dx.doi.org/10.2478/s11532-009-0105-0.

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AbstractOxidatively generated damage to DNA frequently appears in the human genome as an effect of aerobic metabolism or as the result of exposure to exogenous oxidizing agents. Due to these facts it was decided to present, for the first time, the electron affinity, ionization potential of 5′,8-cyclo-2′-deoxyadenosine/guanosine (cdA, cdG) in their 5′R and 5′S diastereomeric forms. For all points of quantum mechanics studies presented, the density functional theory (DFT) with B3LYP parameters on 6-311++G** basis set level was used. The zero-point vibrational corrected adiabatic electron affinity (AEA) and adiabatic ionization potential (AIP) were calculated. Additionally the vertical electron affinity (VEA), vertical detachment energy (VDE) and vertical ionization potential were taken into consideration. AEA in eV (gaseous/aqueous phase) are as follows: 0.3/1.81 (5′R)cdA, 0.13/1.76 (5′S)cdA, 0.17/1.49 (5′R)cdG, 0.14/1.53 (5′S)cdG and AIP followed the order 7.43/5.59(5′S)cdG, 7.49/5.60(5′R)cdG, 7.77/5.97(5′R)cdA, 7.84/5.93(5′S)cdA. The obtained AIPs were found to be lower than that for corresponding natural nucleosides. Therefore, even though the 5′,8-cyclopurine-2′-deoxynucleoside level in a cell was judged as low, they can play an important role in the stability, replication and transcription of genes.

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Arıca, M. Yakup, H. Nur Testereci, and Adil Denizli. "Dye–ligand and metal chelate poly(2-hydroxyethylmethacrylate) membranes for affinity separation of proteins." Journal of Chromatography A 799, no. 1-2 (March 1998): 83–91. http://dx.doi.org/10.1016/s0021-9673(97)01079-0.

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Matainaho, T., E. J. Cragoe, S. W. Manley, G. J. Huxham, J. V. Pearson, and J. R. Bourke. "Inhibitory effects of amiloride and its analogues on prostaglandin E2-stimulated fluid transport by cultured porcine thyroid cells: evidence for apical membrane Na+ channels." Journal of Endocrinology 123, no. 1 (October 1989): 93–97. http://dx.doi.org/10.1677/joe.0.1230093.

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ABSTRACT Confluent monolayers of cultured porcine thyroid cells transport fluid from the apical to the basal surface, forming circumscribed zones of detachment (domes) from the culture dish substrate. Fluid transport, as measured by increase in dome height, was stimulated by prostaglandin E2 (PGE2; 1 μmol/l) and inhibited by amiloride (0·1–100 μmol/l). Values of the inhibition constant (Ki) with 95% confidence limits for each of a series of amiloride analogues were: 3′,4′-dichlorobenzamil (DCB), 0·090 (0·045–0·18) μmol/l; 2′,4′;-dimethylbenzamil (DMB), 0·14 (0·074–0·27) μmol/l; amiloride, 0·72 (0·33–1·8) μmol/l; 5-(N,N-hexamethylene)amiloride (HMA), 17 (5·9–43) μmol/l; 5-(N-ethyl-N-isopropyl)amiloride (EIPA), 33 (15–71) μmol/l; and 2-guanidinobenzimidazole, 243 (110–570) μmol/l. Triaminopyrimidine was ineffective at concentrations up to 1 mmol/l. Since DCB and DMB are known to have a higher affinity for Na+ channels, while HMA and EIPA show higher affinity for Na+/H+ antiports, it was concluded that PGE2-stimulated fluid transport involved an apical membrane Na+ channel. Journal of Endocrinology (1989) 123, 93–97

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Wright, M. M., I. J. Lean, E. Herrera, and P. F. Dodds. "Changes in the composition of plasma very low density lipoprotein during pregnancy and lactation in genetic lines of pigs." Animal Science 61, no. 2 (October 1995): 361–68. http://dx.doi.org/10.1017/s1357729800013916.

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AbstractPlasma very low density lipoproteins (VLDL) of gilts were separated into two sub fractions according to their affinity for heparin. The proportion of VLDL present as subfraction 2 (higher affinity for heparin) varied, according to the genetic line of the pigs, between 0·21 and 0·78 in virgin gilts. The proportions were related to the variation in piglet survival in the same nine genetic lines by a quadratic equation, which predicted that greater than 90% survival to weaning was to be found in piglets born to gilts having between about 0·3 and 0·7 of their VLDL as subfraction 2. This observation suggests a simple measurement that could be used in the selection of sows for a breeding programme. The proportion of subfraction 2 fell throughout pregnancy in each of three genetic lines measured and only returned to pre-pregnant values after weaning: these changes did not correlate with the changes in the lipid composition of plasma VLDL measured during pregnancy and lactation. The findings suggest a role for the VLDL subfractions in controlling the nutrition of the neonatal pig.

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Knauf, P. A., N. A. Mann, J. E. Kalwas, L. J. Spinelli, and M. Ramjeesingh. "Interactions of NIP-taurine, NAP-taurine, and Cl- with the human erythrocyte anion exchange system." American Journal of Physiology-Cell Physiology 253, no. 5 (November 1, 1987): C652—C661. http://dx.doi.org/10.1152/ajpcell.1987.253.5.c652.

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N-(4-isothiocyano-2-nitrophenyl)-2-aminoethanesulfonate (NIP-taurine), a newly synthesized isothiocyano derivative of N-(4-azido-2-nitrophenyl)-2-aminoethanesulfonate (NAP-taurine), is a potent inhibitor of human erythrocyte chloride exchange. At 0 degrees C, the inhibition is reversible, but at 37 degrees C, NIP-taurine inhibits irreversibly, indicating that it may be a useful label for its binding site. When present at the outside of the cell, NIP-taurine binds with low affinity to a site that seems to be the Cl- transport site (on the basis of its affinity for Cl-) and with much higher affinity to a different site, MN, which has a much lower affinity for Cl-. In this respect, NIP-taurine resembles NAP-taurine, and an analysis of interactions between these two probes is consistent with the idea that they bind to the same two sites. The affinity of NIP-taurine for the high-affinity MN site is enhanced by about fourfold when the transport protein, band 3, is in the conformation with the transport site facing outward (Eo), as compared with the conformation with the transport site facing inward (Ei). External Cl-, but not cytoplasmic Cl-, competes with NIP-taurine for binding to the external, high affinity site. Thus NIP-taurine provides a label for an external site, at which Cl- and perhaps other anions bind, which is separate from both the transport site and the cytoplasmic modifier site at which high Cl- concentrations inhibit Cl- exchange.

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Chaidarun, S. S., M. C. Eggo, P. M. Stewart, and M. C. Sheppard. "Modulation of epidermal growth factor binding and receptor gene expression by hormones and growth factors in sheep pituitary cells." Journal of Endocrinology 143, no. 3 (December 1994): 489–96. http://dx.doi.org/10.1677/joe.0.1430489.

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Abstract Epidermal growth factor (EGF) is a potent mitogen for sheep pituitary cells but the factors controlling the binding and expression of EGF and its receptor (EGFR) in the pituitary are poorly understood. Regulation of EGF binding and EGFR gene expression may determine cellular responsiveness to EGF and could play a role in neoplastic development. Scatchard analysis of 125I-EGF binding in cultured sheep pituitary cells revealed two receptor binding sites (high affinity class of 2·5± 0·5 × 103 receptors/cell with a dissociation affinity constant (Kd) of 3·2± 0·7 × 1010m and low affinity class of 3·3 ±1·0 × 104 receptors/cell with a Kd of 71 ±1·3 × 10−9 m). Exposure of the cultured cells to some target gland hormones of the pituitary (oestrogen, tri-iodothyronine and hydrocortisone), pituitary growth factors (EGF, basic fibroblast growth factor, transforming growth factor-β and a tumour-promoting phorbol ester (TPA) resulted in an increase in the binding affinity of the high affinity receptors while reducing the receptor number and also a reduction of EGFR mRNA levels, shown by Northern blot analysis. In contrast, forskolin, an activator of adenylate cyclase, showed no significant effect on EGF binding and receptor gene expression. We conclude that the EGFR in normal pituitary cells can be modulated by several hormones and other growth factors at both receptor binding and mRNA levels. Transmodulation of EGFR by hormones and growth factors in the pituitary may be one of the regulatory mechanisms controlling the balance of normal pituitary growth and function. Defects in this regulatory system could have a role in the multistep process of pituitary tumourigenesis. Journal of Endocrinology (1994) 143, 489–496

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Winder, S. J., S. D. Wheatley, and I. A. Forsyth. "Receptor binding of insulin-like growth factor-I to mammary microsomes from non-pregnant, pregnant and lactating sheep." Journal of Endocrinology 136, no. 2 (February 1993): 297–304. http://dx.doi.org/10.1677/joe.0.1360297.

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ABSTRACT Sucrose density centrifugation was used to prepare a partially purified membrane fraction from the mammary glands of non-pregnant, pregnant and lactating sheep. The binding of125 I-labelled insulin-like growth factor-I (IGF-I) was dependent on membrane protein concentration, pH, time and temperature. The binding showed the characteristics of a type-1 IGF receptor, being displaced by IGF-I (median effective dose (ED50) 0·55 nmol/l), less effectively by IGF-II (ED50 8·8 nmol/l) and least effectively by insulin. Glucagon, ovine prolactin and ovine placental lactogen could not displace binding. A molecular weight of 135 000 was determined by affinity cross-linking using disuccinimidyl suberate; this was consistent with the reported size of the type-1 receptor α-subunit. Scatchard analysis was used to determine binding affinity and numbers of IGF-I-binding sites. A single class of high-affinity binding sites was found in all physiological states. In non-pregnant sheep and sheep at days 40, 75 and 110–120 of pregnancy and at term, the binding affinity was similar (apparent dissociation constant (Kd) 2·73 ±0·31 nmol/l, n = 22). In lactating sheep (weeks 1, 4 and 10), the binding affinity was significantly (P = 0·02) higher (Kd 0·77± 0·06 nmol/l n = 9). Binding capacity was similar in non-pregnant and pregnant sheep (1005 ± 113 fmol/mg, n = 19), but fell by parturition and remained low in lactation (570±52 fmol/mg membrane protein, n = 12). The results suggest that the mammary growth of pregnancy is not regulated at the level of the type-1 IGF receptor. Journal of Endocrinology (1993) 136, 297–304

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Bolton, David, Izzy Boyfield, Martyn C. Coldwell, Michael S. Hadley, Amanda Johns, Christopher N. Johnson, Roger E. Markwell, et al. "2-[(substituted)phenyl]-5-[1-(2-phenylazacycloheptyl)methyl]-1H-pyrroles with high affinity and selectivity for the dopamine D3 receptor." Bioorganic & Medicinal Chemistry Letters 7, no. 4 (February 1997): 485–88. http://dx.doi.org/10.1016/s0960-894x(97)00045-0.

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Pérez-Garrido, Alfonso, Virginia Rivero-Buceta, Gaspar Cano, Sanjay Kumar, Horacio Pérez-Sánchez, and Marta Teijeira Bautista. "Latest QSAR study of adenosine A $$_{\mathrm{2B}}$$ 2 B receptor affinity of xanthines and deazaxanthines." Molecular Diversity 19, no. 4 (July 10, 2015): 975–89. http://dx.doi.org/10.1007/s11030-015-9608-0.

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Buckanovich, R. J., and R. B. Darnell. "The neuronal RNA binding protein Nova-1 recognizes specific RNA targets in vitro and in vivo." Molecular and Cellular Biology 17, no. 6 (June 1997): 3194–201. http://dx.doi.org/10.1128/mcb.17.6.3194.

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Nova-1, an autoantigen in paraneoplastic opsoclonus myoclonus ataxia (POMA), a disorder associated with breast cancer and motor dysfunction, is a neuron-specific nuclear RNA binding protein. We have identified in vivo Nova-1 RNA ligands by combining affinity-elution-based RNA selection with protein-RNA immunoprecipitation. Starting with a pool of approximately 10(15) random 52-mer RNAs, we identified long stem-loop RNA ligands that bind to Nova-1 with high affinity (Kd of approximately 2 nM). The loop region of these RNAs harbors a approximately 15-bp pyrimidine-rich element [UCAU(N)(0-2)]3 which is essential for Nova-1 binding. Mutagenesis studies defined the third KH domain of Nova-1 and the [UCAU(N)(0-2)]3 element as necessary for in vitro binding. Consensus [UCAU (N)(0-2)], elements were identified in two neuronal pre-mRNAs, one encoding the inhibitory glycine receptor alpha2 (GlyR alpha2) and a second encoding Nova-1 itself. Nova-1 protein binds these RNAs with high affinity and specificity in vitro, and this binding can be blocked by POMA antisera. Moreover, both Nova-1 and GlyR alpha2 pre-mRNAs specifically coimmunoprecipitated with Nova-1 protein from brain extracts. Thus, Nova-1 functions as a sequence-specific nuclear RNA binding protein in vivo; disruption of the specific interaction between Nova-1 and GlyR alpha2 pre-mRNA may underlie the motor dysfunction seen in POMA.

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Avenell, Kim Y., Izzy Boyfield, Michael S. Hadley, Christopher N. Johnson, David J. Nash, Graham J. Riley, and Geoffrey Stemp. "Heterocyclic analogues of 2-aminotetralins with high affinity and selectivity for the dopamine D3 receptor." Bioorganic & Medicinal Chemistry Letters 9, no. 18 (September 1999): 2715–20. http://dx.doi.org/10.1016/s0960-894x(99)00454-0.

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Biberger, C., and E. von Angerer. "2-Phenylindoles with sulfur containing side chains. Estrogen receptor affinity, antiestrogenic potency, and antitumor activity." Journal of Steroid Biochemistry and Molecular Biology 58, no. 1 (April 1996): 31–43. http://dx.doi.org/10.1016/0960-0760(96)00004-0.

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25

Maeda, Dean Y., Wanda Williams, Wes E. Kim, Linn N. Thatcher, Wayne D. Bowen, and Andrew Coop. "N-Arylalkylpiperidines as High-Affinity Sigma-1 and Sigma-2 Receptor Ligands: Phenylpropylamines as Potential Leads for Selective Sigma-2 Agents." Bioorganic & Medicinal Chemistry Letters 12, no. 3 (February 2002): 497–500. http://dx.doi.org/10.1016/s0960-894x(01)00788-0.

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26

Hogues, Hervé, Traian Sulea, Francis Gaudreault, Christopher R. Corbeil, and Enrico O. Purisima. "Binding pose and affinity prediction in the 2016 D3R Grand Challenge 2 using the Wilma-SIE method." Journal of Computer-Aided Molecular Design 32, no. 1 (October 5, 2017): 143–50. http://dx.doi.org/10.1007/s10822-017-0071-0.

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27

Stewart, Jennifer M., Eric S. Kilpatrick, Sylvia Cathcart, Michael Small, and Marek H. Dominiczak. "Low-Density Lipoprotein Particle Size in Type 2 Diabetic Patients and Age Matched Controls." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 31, no. 2 (March 1994): 153–59. http://dx.doi.org/10.1177/000456329403100207.

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Non-enzymatic glycation of low-density lipoprotein (LDL), and the predominance of small dense LDL particles may together contribute to the increased risk of atherosclerosis in diabetes. We aimed to establish whether the size of LDL particles is related to plasma triglyceride concentration, and to the extent of LDL glycation in type 2 diabetic patients. Sixteen men with type 2 diabetes and 16 age matched non-diabetic controls were studied. LDL size was measured by rapid density gradient ultracentrifugation, and LDL glycation by affinity chromatography. Modal LDL density correlated with plasma triglyceride concentrations in both diabetic and control groups ( r = 0·86, P<0·000, and r=0·76, P<0·0008, respectively). There was no significant difference in these variables between the groups. LDL modal density showed no correlation with HbA1, serum fructosamine or plasma glucose in either group. In the diabetic group the degree of LDL glycation correlated with serum fructosamine ( r = 0·74, P<0·001), HbA1 ( r=0·65, P<0·008), and with plasma glucose ( r=0·64, P<0·008). Our results suggest that, in well controlled type 2 diabetic patients LDL size is independent of short-term glycaemic control but can be predicted by plasma triglyceride concentrations.

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Jeck, Reinhard, Michael Scholze, Anja Tischlich, Christoph Woenckhaus, and Jürgen Zimmermann. "New Reactive Coenzyme Analogues for Affinity Labeling of NAD+ and NADP+ Dependent Dehydrogenases." Zeitschrift für Naturforschung C 50, no. 7-8 (August 1, 1995): 476–86. http://dx.doi.org/10.1515/znc-1995-7-803.

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Abstract Reactive coenzyme analogues ω-(3-diazoniumpyridinium)alkyl adenosine diphosphate were prepared by reaction of ω-(3-aminopyridinium)alkyl adenosine diphosphate with nitrous acid. In these compounds the nicotinamide ribose is substituted by hydrocarbon chains of varied lengths (n-ethyl to n-pentyl). The diazonium compounds are very unstable and decompose rapidly at room temperature. They show a better stability at 0 °C. L actate and alcohol dehydrogenase do not react with any of the analogues. Glyceraldehyde-3-phosphate dehydrogenase reacts rapidly with the diazonium pentyl compound. Decreasing the length of the alkyl chain significantly decreases the inactivation velocity. 3α,20β-Hydroxysteroid dehydrogenase reacts at 0 °C with the ethyl homologue and slowly with the propyl compound. The butyl-and pentyl analogues do not inactivate at 0 °C. Tests with 14C -labeled 2-(3-diazoniumpyridinium)ethyl adenosine diphosphate show that complete loss of enzyme activity results after incorporation of 2 moles of inactivator into 1 mole of tetrameric enzyme. 4-(3-Acetylpyridinium)butyl 2 ′-phospho-adenosine diphosphate, a structural analogue of NADP +, was prepared by condensation of adenosine-2,3-cyclophospho-5′-phosphomorpholidate with (3-acetylpyridinium)butyl phosphate, followed by hydrolysis of the cyclic phosphoric acid ester with 2 ′:3′-cyclonucleotide-3′-phosphodiesterase. Because of the redox potential (-315 mV) and the distance between the pyridinium and phosphate groups, this analogue is a hydrogen acceptor and its reduced form a hydrogen donor in tests with alcohol dehyd rogenase from Thermoanaerobium brockii. The reduced form of the coenzyme analogue also is a hydrogen donor with glutathione reductase. With other NADP +-dependent dehydrogenases the com pound has been show n to be a competitive inhibitor against the natural coenzyme. The acetyl group reacts with bromine to form the bromoacetyl group. This reactive bromoacetyl analogue is a specific active-site directed irreversible inhibitor of isocitrate dehydrogenase.

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Ramanathan, Muthukumar, Ian D. Ferguson, Weili Miao, and Paul A. Khavari. "SARS-CoV-2 B.1.1.7 and B.1.351 spike variants bind human ACE2 with increased affinity." Lancet Infectious Diseases 21, no. 8 (August 2021): 1070. http://dx.doi.org/10.1016/s1473-3099(21)00262-0.

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30

Makkar, H. P. S., and K. Becker. "Adaptation of cattle to tannins: rôle of proline-rich proteins in oak-fed cattle." Animal Science 67, no. 2 (October 1998): 277–81. http://dx.doi.org/10.1017/s1357729800010031.

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AbstractSaliva and faecal samples were collected from hill cattle (no. = 10) given tannin-rich oak (Quercus incana) leaves in the north-west Himalayan region of India. Amino acid composition of the saliva samples after thawing to remove precipitated proteins by centrifugation, and dialysis (molecular weight cut off: 3500) to remove small moieties revealed 6·4 (s.d. 0·6) % proline, 15·6 (s.d. 0·6) % glutamine plus glutamate and 9·2 (s.d. 1·0) % glycine on molar basis. For Holstein Friesian cattle (no. = 4) which had no history of consumption of tannin-containing foods, these values were 6·5 (s.d. 0·4) %, 15·2 (s.d. 0·5) % and 9·8 (s.d. 0·7) % respectively. Proline concentration in the proteins present either as free or as tannin-protein complexes in the lyophilized faecal samples from hill cattle was 4·7 (s.d. 0·2) % (on molar basis) of the total amino acids and 5·3 (s.d. 0·2) % in Holstein Friesian cattle. In the faeces of oak-fed cattle, the tannin and condensed tannin levels on dry-weight basis were 0·81 (s.d. 0·20) % as tannin acid equivalent and 0·06 (s.d. 0·04) % as leucocyanidin equivalent respectively. For tannic acid, the relative affinity of salivary proteins, using the competitive binding assay, was about six-times higher than that of bovine serum albumin (BSA) and was of the same order as that of gelatin. Turbidity of complexes formed between salivary proteins or BSA and tannic acid showed proportionately about 0·50 lower turbidity for salivary proteins in 0-2 mol/I acetate buffer (pH 4·9 containing 0·17 mol/l NaCl) and proportionately about 0·84 lower turbidity in distilled water. The results suggest that unlike rats or mice, the proline-rich proteins do not appear to be of any physiological significance in the adaptation of cattle to tannins. However, the salivary proteins of cattle though not rich in proline, have a high affinity for tannins and these proteins have a high tendency to form soluble tannin-protein complexes.

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Weber, Matthias M., Christoph J. Auernhammer, Wieland Kiess, and Dieter Engelhardt. "Insulin-like growth factor receptors in normal and tumorous adult human adrenocortical glands." European Journal of Endocrinology 136, no. 3 (March 1997): 296–303. http://dx.doi.org/10.1530/eje.0.1360296.

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Abstract We have identified and characterized insulin-like growth factor (IGF)-I and IGF-II/mannose-6phosphate (IGF-II/M6P) receptors in normal adult human adrenocortical tissue. Furthermore, we investigated the IGF-I receptor concentration and binding characteristics in benign and carcinomatous adrenocortical tumors. Membrane preparations of 14 normal adrenocortical glands showed a mean specific 125I-IGF-I binding (SB) of 5·0±0·5% and a competition by unlabeled ligands which is characteristic of the IGF-I receptor. The Scatchard analysis revealed a single class of high affinity binding sites with a dissociation constant (Kd) of 0·16±0·03 nmol/l, and a receptor concentration (RC) of 19·2±2·5 nmol/kg protein. Affinity cross-linking experiments with normal and tumorous adrenocortical tissue displayed a band at an apparent molecular mass of 135 kDa, corresponding to the size of the normal α-subunit of the IGF-I receptor. In agreement, 125I-IGF-II binding to normal adult human adrenocortical membranes was characteristic for the IGF-II/M6P receptor, and the Scatchard analysis revealed the presence of a single class of high affinity binding sites (SB 7·5±0·5, RC 1137±265 nmol/kg protein, Kd 2·20±0·46 nmol/l, n=6). The identity of the IGF-II/M6P receptor in adrenocortical tissue was further confirmed by Western blotting showing a specific band at 220 kDa. When 125I-IGF-I binding in adrenocortical hyperplasias (SB 4·1±0·4% RC 19·6± 2·0 nmol/kg protein, Kd 0·19±0·04 nmol/l, n=4) and adenomas (SB 4·0±1·1% RC 17·5± 3·1 nmol/kg protein, Kd 0·21±0·nmol/l,04 n=4) was compared with the 125I-IGF-I binding in normal adrenocortical tissue, similar IGF-I receptor concentration and binding kinetics were found. In contrast, three out of four hormonally active adrenocortical carcinomas showed a strongly elevated specific 125I-IGF-I binding with a 3- to 4-fold increase in IGF-I receptor concentration, as compared with normal adrenocortical tissue. This resulted in a significantly higher mean specific binding and receptor concentration in adrenocortical carcinomas, while the binding kinetics and the size of the α-subunit of the IGF-I receptor remained unaltered (n =4, SB 13·8±4·2%, RC 72·2 ± 21·3 nmol/kg protein, Kd 0·17±0·02 nmol/l). In summary, we show that intact IGF-I and IGF-II receptors are present in normal adult human adrenocortical tissue. While the abundance of the IGF-I receptor in adrenocortical hyperplasias and adenomas was similar to normal tissue, a strong overexpression of the intact IGF-I receptor was found in three out of four adrenocortical carcinomas. European Journal of Endocrinology 136 296–303

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32

Lepetit, Christine, Mogens Brøndsted Nielsen, François Diederich, and Remi Chauvin. "Cover Picture: Aromaticity and Electron Affinity of Carbok-[3]radialenes,k=0, 1, 2 (Chem. Eur. J. 20/2003)." Chemistry - A European Journal 9, no. 20 (October 17, 2003): 4841. http://dx.doi.org/10.1002/chem.200390253.

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33

Yang, Yang, Jia Xin Zhang, Lin Zhu, and Huabei Zhang. "Synthesis, Novel Crystal Structure, andβ-Amyloid Binding Property of Re(I)(tricarbonyl)+EHIDA Analogue." Bioinorganic Chemistry and Applications 2009 (2009): 1–7. http://dx.doi.org/10.1155/2009/702730.

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A neutral compound Re(CO)3(L) (L: 2-((2-(2,6-diethylphenylamino)-2-oxoethyl)(2-ethoxy-2-oxoethyl)amino)acetic acid, an IDA analogue) has been synthesized and evaluated for in vitro imaging probes ofβ-amyloid (Aβ) aggregates. Results of X-ray measurement of Re(CO)3(L) demonstrated that the coordination mode of Re(CO)3(L) was different from that of classical Re/Tc(I) (tricarbonyl)-IDA analogues; the structure of Re(CO)3(L) was confirmed by means of infrared spectrum, HPLC-UV, TOF MS, and X-ray measurements (Cambridge Crystallographic Data Centre number is 732731): monoclinicP21/c,a=15.6636(12) Å,b=10.9360(8) Å,c=27.756(2) Å,α=90.000(0)∘,β=90.783(5)∘,γ=90.000(0)∘, andZ=8. The binding affinity forβ-amyloid plaques was assessed by in vitro binding assay using preformed synthetic Aβ(1–40)aggregates. The neutral compound Re(CO)3(L) showed binding affinity to Aβaggregates at micromolar level by fluorescence spectroscopy, and this work will encourage for further exploration of imaging agents labeled byT99mc(CO)3+center as probes forβ-amyloid plaques in vivo.

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Müller, Jens, Ennio Zangrando, Norbert Pahlke, Eva Freisinger, Lucio Randaccio, and Bernhard Lippert. "Affinity of the Iminooxo Tautomer Anion of 1-Methylcytosine intrans-[Pt(NH3)2(1-MeC-N4)2]2+ for Heterometals." Chemistry - A European Journal 4, no. 3 (March 10, 1998): 397–405. http://dx.doi.org/10.1002/(sici)1521-3765(19980310)4:3<397::aid-chem397>3.0.co;2-0.

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35

Devarkar, Swapnil C., Chen Wang, Matthew T. Miller, Anand Ramanathan, Fuguo Jiang, Abdul G. Khan, Smita S. Patel, and Joseph Marcotrigiano. "Structural basis for m7G recognition and 2′-O-methyl discrimination in capped RNAs by the innate immune receptor RIG-I." Proceedings of the National Academy of Sciences 113, no. 3 (January 5, 2016): 596–601. http://dx.doi.org/10.1073/pnas.1515152113.

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RNAs with 5′-triphosphate (ppp) are detected in the cytoplasm principally by the innate immune receptor Retinoic Acid Inducible Gene-I (RIG-I), whose activation triggers a Type I IFN response. It is thought that self RNAs like mRNAs are not recognized by RIG-I because 5′ppp is capped by the addition of a 7-methyl guanosine (m7G) (Cap-0) and a 2′-O-methyl (2′-OMe) group to the 5′-end nucleotide ribose (Cap-1). Here we provide structural and mechanistic basis for exact roles of capping and 2′-O-methylation in evading RIG-I recognition. Surprisingly, Cap-0 and 5′ppp double-stranded (ds) RNAs bind to RIG-I with nearly identical Kd values and activate RIG-I’s ATPase and cellular signaling response to similar extents. On the other hand, Cap-0 and 5′ppp single-stranded RNAs did not bind RIG-I and are signaling inactive. Three crystal structures of RIG-I complexes with dsRNAs bearing 5′OH, 5′ppp, and Cap-0 show that RIG-I can accommodate the m7G cap in a cavity created through conformational changes in the helicase-motif IVa without perturbing the ppp interactions. In contrast, Cap-1 modifications abrogate RIG-I signaling through a mechanism involving the H830 residue, which we show is crucial for discriminating between Cap-0 and Cap-1 RNAs. Furthermore, m7G capping works synergistically with 2′-O-methylation to weaken RNA affinity by 200-fold and lower ATPase activity. Interestingly, a single H830A mutation restores both high-affinity binding and signaling activity with 2′-O-methylated dsRNAs. Our work provides new structural insights into the mechanisms of host and viral immune evasion from RIG-I, explaining the complexity of cap structures over evolution.

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Drbal, Karel, Pavla Angelisova, Jan Cerny, Guenther Staffler, Vaclav Horejsi, and Hannes Stockinger. "Low-affinity Monoclonal Antibodies are useful Tools for Tracking Oligomerized Cell Surface Receptors." Single Molecules 2, no. 2 (July 2001): 150. http://dx.doi.org/10.1002/1438-5171(200107)2:2<150::aid-simo150>3.0.co;2-0.

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37

Corda, M. G., O. Giorgi, B. Longoni, E. Ongini, S. Montaldo, and G. Biggio. "Preferential affinity of 3H-2-oxo-quazepam for type I benzodiazepine recognition sites in the human brain." Life Sciences 42, no. 2 (January 1988): 189–97. http://dx.doi.org/10.1016/0024-3205(88)90682-0.

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38

Boreström, Cecilia, Alma Forsman, Ulla Rüetschi, and Lars Rymo. "E2F1, ARID3A/Bright and Oct-2 factors bind to the Epstein–Barr virus C promoter, EBNA1 and oriP, participating in long-distance promoter–enhancer interactions." Journal of General Virology 93, no. 5 (May 1, 2012): 1065–75. http://dx.doi.org/10.1099/vir.0.038752-0.

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The Epstein–Barr virus (EBV) C promoter (Cp) regulates several genes required for B-cell proliferation in latent EBV infection. The family of repeats (FR) region of the latent origin of plasmid replication (oriP) functions as an Epstein–Barr nuclear antigen 1 (EBNA1)-dependent distant enhancer of Cp activity, and the enhancer–promoter interaction is mediated by a higher-order multi-protein complex containing several copies of EBNA1. Using DNA-affinity purification with a 170 bp region of the Cp in combination with mass spectrometry, we identified the cell cycle-regulatory protein E2F1, the E2F-binding protein ARID3A, and the B-cell-specific transcription factor Oct-2 as components of this multi-protein complex. Binding of the three factors to the FR region of oriP was determined by DNA-affinity and immunoblot analysis. Co-immunoprecipitation and proximity ligation analysis revealed that the three factors, E2F1, ARID3A and Oct-2, interact with each other as well as with EBNA1 in the nuclei of EBV-positive cells. Using the chromatin immunoprecipitation assay, we showed that E2F1 and Oct-2 interacted with the FR part of oriP and the Cp, but the ARID3A interaction was, however, only detected at the Cp. Our findings support the hypothesis that EBNA1 initiates transcription at the Cp via interactions between multiple EBNA1 homodimers and cellular transcription factors in a large molecular machinery that forms a dynamic interaction between Cp and FR.

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John, W. G., R. Edwards, and C. P. Price. "Laboratory Evaluation of the DCA 2000 Clinic HbA1c Immunoassay Analyser." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 31, no. 4 (July 1994): 367–70. http://dx.doi.org/10.1177/000456329403100411.

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The DCA 2000™ clinical analyser for the measurement of haemoglobin A1c was evaluated for analytical quality. The analyser, which utilises inhibition of latex agglutination immunoassay, demonstrated good within-batch (1 · 9–3 · 1% CV) and between-batch (2·2% CV) imprecision, and was not affected by haemoglobin concentration. The analyser was linear throughout the analytical range, and was found to correlate well with agar electroendosmosis ( r = 0·93), affinity chromatography ( r=0·97), HPLC ( r=0 · 90) and EIA ( r=0·98). The analyser was found to give reliable analytical results, and with its ease of use, will provide the diabetologist with HbA1c results in the clinic; although an analysis time of 9 min will limit sample throughput.

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40

Toyoda, Koichi, Yoichi Yoshizawa, Hiroyuki Arai, Masaharu Ishii, and Yasuo Igarashi. "The role of two CbbRs in the transcriptional regulation of three ribulose-1,5-bisphosphate carboxylase/oxygenase genes in Hydrogenovibrio marinus strain MH-110." Microbiology 151, no. 11 (November 1, 2005): 3615–25. http://dx.doi.org/10.1099/mic.0.28056-0.

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Hydrogenovibrio marinus MH-110 possesses three different sets of genes for ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO): two form I (cbbLS-1 and cbbLS-2) and one form II (cbbM). We have previously shown that the expression of these RubisCO genes is dependent on the ambient CO2 concentration. LysR-type transcriptional regulators, designated CbbR1 and CbbRm, are encoded upstream of the cbbLS-1 and cbbM genes, respectively. In this study, we revealed by gel shift assay that CbbR1 and CbbRm bind with higher affinity to the promoter regions of cbbLS-1 and cbbM, respectively, and with lower affinity to the other RubisCO gene promoters. The expression patterns of the three RubisCOs in the cbbR1 and the cbbRm gene mutants showed that CbbR1 and CbbRm were required to activate the expression of cbbLS-1 and cbbM, respectively, and that neither CbbR1 nor CbbRm was required for the expression of cbbLS-2. The expression of cbbLS-1 was significantly enhanced under high-CO2 conditions in the cbbRm mutant, in which the expression of cbbM was decreased. Although cbbLS-2 was not expressed under high-CO2 conditions in the wild-type strain or the single cbbR mutants, the expression of cbbLS-2 was observed in the cbbR1 cbbRm double mutant, in which the expression of both cbbLS-1 and cbbM was decreased. These results indicate that there is an interactive regulation among the three RubisCO genes.

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Mahmoud, I. Y., A. E. Colás, M. J. Woller, and R. V. Cyrus. "Cytoplasmic progesterone receptors in uterine tissue of the snapping turtle (Chelydra serpentina)." Journal of Endocrinology 109, no. 3 (June 1986): 385–92. http://dx.doi.org/10.1677/joe.0.1090385.

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ABSTRACT A high affinity progesterone-binding component was detected in the cytosol of the uterus of the snapping turtle, Chelydra serpentina. Density gradient centrifugation indicated that binding of [3H]progesterone and [3H]promegestone (R5020) was to a fraction with a heavier sedimentation coefficient than bovine serum albumin (BSA) appearing as a broader peak in the 6–7 S region; it was not affected by excess cortisol. Another binding peak, lighter than BSA and appearing with [3H]R5020 and [3H]progesterone near the 4 S region, was affected by excess cortisol. Excess progesterone decreased both the heavier and lighter peaks. Analysis of steroid specificity revealed that, of the natural steroids, progesterone had the highest affinity for the uterine cytosol. This was followed by deoxycorticosterone, 5α-pregnanedione, testosterone, oestradiol-17β, corticosterone, 5α-dihydrotestosterone and cortisol. Non-linear regression analysis of saturation data indicated the presence of two classes of high affinity binding sites: progesterone-binding sites (R-sites) with equilibrium association constants (Ka) of 2·9 ± 0·28 litres/nmol (mean ± 95% confidence limit) for [3H]R5020 and 0·34 ± 0·20 litres/nmol for [3H]progesterone, and corticosteroid-binding globulin-like sites (G-sites) with Ka of 4·5 ± 1·6 litres/nmol for progesterone. The concentration of R-sites was between 0·66 ± 0·10 and 2·6 ± 0·55 pmol/mg protein while that of G-sites was between 0·73 ± 0·05 and 5·0 ± 0·27 pmol/mg protein. DEAE-cellulose filtration assay also confirmed the presence of R-sites and G-sites in the cytosol. R-sites were detectable without oestrogen priming during the preovulatory and vitellogenic phases (low progesterone, high oestrogen concentrations) when the ovarian follicles are mature (18–22 mm diameter). During the early postovulatory phase (high progesterone, low oestrogen concentrations), when the ovarian follicles are immature (5–7 mm diameter) and active corpora lutea are present, the R-sites were undetectable even after oestrogen priming. This indicates that progesterone might have an inhibitory and oestrogen a stimulatory role in the regulation of R-sites. J. Endocr. (1986) 109, 385–392

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42

Rong, Haiqin, Eva Hydbring, Kerstin Olsson, William J. Burtis, Wayne Rankin, Vivian Grill, and Elisabet Bucht. "Parathyroid hormone-related protein in neonatal and reproductive goats determined by a sensitive time-resolved immunofluorometric assay." European Journal of Endocrinology 136, no. 5 (May 1997): 546–51. http://dx.doi.org/10.1530/eje.0.1360546.

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Abstract Objective: High concentrations of parathyroid hormone-related protein (PTHrP) have been found in goat milk but it is not known whether it can enter the circulation of the neonate. In this study we have developed a sensitive two-site lanthanide immunofluorometric assay (IFMA) using dissociation and enhancement time-resolved fluorometry to address this question. Method: Affinity-purified anti-PTHrP 38–67 raised in rabbit was biotinylated and immobilized in streptavidin-coated microtitration wells as a 'capture' antibody. As a signal, affinity-purified anti-PTHrP 1–34, raised in sheep, was labeled with an europium chelate. A sensitivity of 0·3 pmol/l was achieved. PTHrP levels were determined in the plasma of eleven neonatal, seven parturient and six non-pregnant, non-lactating goats as well as in goat milk. Results: The circulating PTHrP levels (mean±s.d.) were significantly increased at day 1 (6·1± 1·7 pmol/l; P< 0·01) and day 3 (3·5±0·6 pmol/l; P< 0·05) after birth in the male kids (n = 8) bottle-fed with milk from the dams, compared with before (2·2±0·7 pmol/l)and 30 min after (2·0±0·6 pmol/l) the first feeding and 14 days (2·4±0·8 pmol/l) later. In the female kids (n = 3) fed with formula there was no such increase and the concentrations remained between 1·6–1·9 pmol/l. In the parturient goats the mean±s.d. PTHrP levels before, during and after parturition were 2·9±1·7. 4·2±2·4 and 3·7±2·2 pmol/l respectively (n = 7) which demonstrated that plasma PTHrP was higher during and after parturition in comparison with before (P < 0·05). The levels in non-pregnant, non-lactating goats were 3·3±1·5 pmol/l (n = 6). PTHrP levels in goat milk were in the nanomolar range and were highest in the colostrum. Conclusions: A significant increase of plasma PTHrP was observed in goat kids fed with milk from their dams and this increase was not found in kids fed with formula. Plasma PTHrP was also increased during parturition. European Journal of Endocrinology 136 546–551

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43

Jagadeesan, Balamurugan, Ok Kyung Koo, Kwang-Pyo Kim, Kristin M. Burkholder, Krishna K. Mishra, Amornrat Aroonnual, and Arun K. Bhunia. "LAP, an alcohol acetaldehyde dehydrogenase enzyme in Listeria, promotes bacterial adhesion to enterocyte-like Caco-2 cells only in pathogenic species." Microbiology 156, no. 9 (September 1, 2010): 2782–95. http://dx.doi.org/10.1099/mic.0.036509-0.

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Listeria adhesion protein (LAP), an alcohol acetaldehyde dehydrogenase (lmo1634), interacts with host-cell receptor Hsp60 to promote bacterial adhesion during the intestinal phase of Listeria monocytogenes infection. The LAP homologue is present in pathogens (L. monocytogenes, L. ivanovii) and non-pathogens (L. innocua, L. welshimeri, L. seeligeri); however, its role in non-pathogens is unknown. Sequence analysis revealed 98 % amino acid similarity in LAP from all Listeria species. The N-terminus contains acetaldehyde dehydrogenase (ALDH) and the C-terminus an alcohol dehydrogenase (ADH). Recombinant LAP from L. monocytogenes, L. ivanovii, L. innocua and L. welshimeri exhibited ALDH and ADH activities, and displayed strong binding affinity (K D 2–31 nM) towards Hsp60. Flow cytometry, ELISA and immunoelectron microscopy revealed more surface-associated LAP in pathogens than non-pathogens. Pathogens exhibited significantly higher adhesion (P<0.05) to Caco-2 cells than non-pathogens; however, pretreatment of bacteria with Hsp60 caused 47–92 % reduction in adhesion only in pathogens. These data suggest that biochemical properties of LAP from pathogenic Listeria are similar to those of the protein from non-pathogens in many respects, such as substrate specificity, immunogenicity, and binding affinity to Hsp60. However, protein fractionation analysis of extracts from pathogenic and non-pathogenic Listeria species revealed that LAP was greatly reduced in intracellular and cell-surface protein fractions, and undetectable in the extracellular milieu of non-pathogens even though the lap transcript levels were similar for both. Furthermore, a LAP preparation from L. monocytogenes restored adhesion in a lap mutant (KB208) of L. monocytogenes but not in L. innocua, indicating possible lack of surface reassociation of LAP molecules in this bacterium. Taken together, these data suggest that LAP expression level, cell-surface localization, secretion and reassociation are responsible for LAP-mediated pathogenicity and possibly evolved to adapt to a parasitic life cycle in the host.

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Jin, Jean Huaqian, and Andreas Seyfang. "High-affinity myo-inositol transport in Candida albicans: substrate specificity and pharmacology." Microbiology 149, no. 12 (December 1, 2003): 3371–81. http://dx.doi.org/10.1099/mic.0.26644-0.

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Inositol is considered a growth factor in yeast cells and it plays an important role in Candida as an essential precursor for phospholipomannan, a glycophosphatidylinositol (GPI)-anchored glycolipid on the cell surface of Candida which is involved in the pathogenicity of this opportunistic fungus and which binds to and stimulates human macrophages. In addition, inositol plays an essential role in the phosphatidylinositol signal transduction pathway, which controls many cell cycle events. Here, high-affinity myo-inositol uptake in Candida albicans has been characterized, with an apparent K m value of 240±15 μM, which appears to be active and energy-dependent as revealed by inhibition with azide and protonophores (FCCP, dinitrophenol). Candida myo-inositol transport was sodium-independent but proton-coupled with an apparent K m value of 11·0±1·1 nM for H+, equal pH 7·96±0·05, suggesting that the C. albicans myo-inositol–H+ transporter is fully activated at physiological pH. C. albicans inositol transport was not affected by cytochalasin B, phloretin or phlorizin, an inhibitor of mammalian sodium-dependent inositol transport. Furthermore, myo-inositol transport showed high substrate specificity for inositol and was not significantly affected by hexose or pentose sugars as competitors, despite their structural similarity. Transport kinetics in the presence of eight different inositol isomers as competitors revealed that proton bonds between the C-2, C-3 and C-4 hydroxyl groups of myo-inositol and the transporter protein play a critical role for substrate recognition and binding. It is concluded that C. albicans myo-inositol–H+ transport differs kinetically and pharmacologically from the human sodium-dependent myo-inositol transport system and constitutes an attractive target for delivery of cytotoxic inositol analogues in this pathogenic fungus.

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Panteghini, M., R. Bonora, and F. Pagani. "Determination of Glycated Apolipoprotein B in Serum by a Combination of Affinity Chromatography and Immunonephelometry." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 31, no. 6 (November 1994): 544–49. http://dx.doi.org/10.1177/000456329403100603.

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We have developed and optimized a procedure for the quantitation of non-enzymatically glycated apolipoprotein B (apo B). Glycated and non-glycated apo B were separated from serum using m-aminophenylboronate affinity chromatography, determined by immunophelometry and the percentage of glycated apo B was calculated. The measuring range of the assay was 2·9–185 mg/dL apo B. The within- and between-run coefficients of variation were <7·4% and 14·6%, respectively, and recovery was >98%. Free glucose in serum did not affect the results at concentrations below 25 mmol/L. In 45 non-diabetic subjects the mean concentration of glycated apo B was 4.3% (SD 1%). In type 1 ( n = 17) and Type 2 ( n = 60) diabetic patients the mean glycated apo B concentrations were 5·3% (SD 0·7%) and 5·9% (SD 1·1%), respectively, significantly higher than in controls ( P<0·001).

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Wang, Gan, Meng-Li Yang, Zi-Lei Duan, Feng-Liang Liu, Lin Jin, Cheng-Bo Long, Min Zhang, et al. "Dalbavancin binds ACE2 to block its interaction with SARS-CoV-2 spike protein and is effective in inhibiting SARS-CoV-2 infection in animal models." Cell Research 31, no. 1 (December 1, 2020): 17–24. http://dx.doi.org/10.1038/s41422-020-00450-0.

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AbstractInfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic worldwide. Currently, however, no effective drug or vaccine is available to treat or prevent the resulting coronavirus disease 2019 (COVID-19). Here, we report our discovery of a promising anti-COVID-19 drug candidate, the lipoglycopeptide antibiotic dalbavancin, based on virtual screening of the FDA-approved peptide drug library combined with in vitro and in vivo functional antiviral assays. Our results showed that dalbavancin directly binds to human angiotensin-converting enzyme 2 (ACE2) with high affinity, thereby blocking its interaction with the SARS-CoV-2 spike protein. Furthermore, dalbavancin effectively prevents SARS-CoV-2 replication in Vero E6 cells with an EC50 of ~12 nM. In both mouse and rhesus macaque models, viral replication and histopathological injuries caused by SARS-CoV-2 infection are significantly inhibited by dalbavancin administration. Given its high safety and long plasma half-life (8–10 days) shown in previous clinical trials, our data indicate that dalbavancin is a promising anti-COVID-19 drug candidate.

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Pliška, V., and H. Kohlhauf Albertin. "Effect of Mg2+ on the binding of oxytocin to sheep myometrial cells." Biochemical Journal 277, no. 1 (July 1, 1991): 97–101. http://dx.doi.org/10.1042/bj2770097.

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Binding isotherms of oxytocin to sheep myometrial cells in a short-term cell culture were investigated in the presence of Mg2+ in the concentration range 0-10 mM. The occurrence of at least three binding sites had been demonstrated earlier. Mg2+ influences individual sites and individual features of the binding isotherm differently. Dissociation constants (Kd) of the high- and medium-affinity sites attain a minimum of 6.8 x 10(-10) and 4.2 x 10(-8) mol/l respectively at 2.75 mM-Mg2+. The two sites display the highest binding capacity (B) at 1 mM-Mg2+ (ratio of high affinity/medium affinity is 1:16). The B/Kd quotients reflecting relative binding (bound-to-free concentration) at the half-saturation of binding sites also have their maxima at 1 mM-Mg2+. The high-affinity site displays a strong positive co-operativity (Hill coefficient at 4 mM-Mg2+ of 2.4), which is amplified in the presence of Mg2+. Positive co-operativity of the medium-affinity site is markedly lower (Hill coefficient at 4 mM-Mg2+ of 1.5) and shows less dramatic Mg(2+)-dependence. Low-affinity sites are not co-operative at any Mg2+ concentration. It is concluded that Mg2+ may display its effect upon the oxytocin-receptor interaction predominantly by influencing positive co-operativity.

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Long, Ya-Qiu, Johannes H. Voigt, Feng-Di T. Lung, C. Richter King, and Peter P. Roller. "Significant compensatory role of position Y-2 conferring high affinity to non-phosphorylated inhibitors of Grb2-SH2 domain." Bioorganic & Medicinal Chemistry Letters 9, no. 15 (August 1999): 2267–72. http://dx.doi.org/10.1016/s0960-894x(99)00379-0.

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Liu, J. P., K. A. Powell, T. C. Südhof, and P. J. Robinson. "Dynamin I is a Ca(2+)-sensitive phospholipid-binding protein with very high affinity for protein kinase C." Journal of Biological Chemistry 269, no. 33 (August 1994): 21043–50. http://dx.doi.org/10.1016/s0021-9258(17)31927-0.

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Halaihel, Nabil, Daniele Gerbaud, Monique Vasseur, and Francisco Alvarado. "Heterogeneity of pig intestinald-glucose transport systems." American Journal of Physiology-Cell Physiology 277, no. 6 (December 1, 1999): C1130—C1141. http://dx.doi.org/10.1152/ajpcell.1999.277.6.c1130.

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Heterogeneity of intestinald-glucose transport is demonstrated using pig jejunal brush-border membrane vesicles in the presence of 100/0 (out/in) mM gradients each of NaCl, NaSCN, and KSCN. Two d-glucose transport systems are kinetically distinguished: high-affinity, low-capacity system 1, which is equivalent to the symporter SGLT1; and low-affinity, high-capacity system 2, which is not a member of the SGLT family but is a d-glucose and d-mannose transporter exhibiting no preference for Na+over K+. A nonsaturabled-glucose uptake component has also been detected; uptake of this component takes place at rates 10 times the rate of components characterizing the classical diffusion marker l-glucose. It is also shown that, in this kinetic work, 1) use of d-glucose-contaminatedd-sorbitol as an osmotic replacement cannot cause the spurious appearance of nonexistent transport systems and 2) a large range (≥50 mM) of substrate concentrations is required to correctly fit substrate saturation curves to distinguish between low-affinity transport systems and physical diffusion.

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Journal articles on the topic 'Affinity 2.0'

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