scholarly journals Relations between high-affinity binding sites for l-tryptophan, diazepam, salicylate and Phenol Red on human serum albumin

1983 ◽  
Vol 209 (1) ◽  
pp. 135-142 ◽  
Author(s):  
U Kragh-Hansen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Binding Sites ◽  
Association Constants ◽  
The Other ◽  
Affinity Binding ◽  
Phenol Red ◽  
High Affinity Binding ◽  
High Affinity ◽  
High Affinity Binding Site

Binding of L-tryptophan, diazepam, salicylate and Phenol Red to defatted human serum albumin was studied by ultrafiltration at pH 7.0. All ligands bind to one high-affinity binding site with association constants of the order of 10(4)-10(5)M-1. The number of secondary binding sites was found to vary from zero to five, with association constants about 10(3)M-1. Competitive binding studies with different pairs of the ligands were performed. Binding of both ligands was determined simultaneously. L-Tryptophan and diazepam were found to compete for a common high-affinity binding site on albumin. The following combinations of ligands do not bind competitively to albumin: L-tryptophan-Phenol Red, L-tryptophan-salicylate and Phenol Red-salicylate. On the other hand, high-affinity bindings of the three ligands do not take place independently but in such a way that binding of one of the ligands results in a decrease in binding of the other ligands. The decreases in binding are reciprocal and can be accounted for by introducing a coupling constant. The magnitude of the constant is dependent on the ligands being bound. In the present study, the mutual decrease in binding was more pronounced with L-tryptophan-salicylate and Phenol Red-salicylate than with L-tryptophan-Phenol Red.

scholarly journals Relations between high-affinity binding sites of markers for binding regions on human serum albumin

1985 ◽  
Vol 225 (3) ◽  
pp. 629-638 ◽  
Author(s):  
U Kragh-Hansen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Binding Sites ◽  
Affinity Binding ◽  
Phenol Red ◽  
Coupling Constant ◽  
High Affinity Binding ◽  
High Affinity ◽  
High Affinity Binding Site

Binding of warfarin, digitoxin, diazepam, salicylate and Phenol Red, individually or in different pair combinations, to defatted human serum albumin at ligand/protein molar ratios less than 1:1 was studied at pH 7.0. The binding was determined by ultrafiltration. Some of the experiments were repeated with the use of equilibrium dialysis in order to strengthen the results. Irrespective of the method used, all ligands bind to one high-affinity binding site with an association constant in the range 10(4)-10(6) M-1. High-affinity binding of the following pair of ligands took place independently: warfarin-Phenol Red, warfarin-diazepam, warfarin-digitoxin and digitoxin-diazepam. Simultaneous binding of warfarin and salicylate led to a mutual decrease in binding of one another, as did simultaneous binding of digitoxin and Phenol Red. Both effects could be accounted for by a coupling constant. The coupling constant is the factor by which the primary association constants are affected; in these examples of anti-co-operativity the factor has a value between 0 and 1. In the first example it was calculated to be 0.8 and in the latter 0.5. Finally, digitoxin and salicylate were found to compete for a common high-affinity binding site. The present findings support the proposal of four separate primary binding sites for warfarin, digitoxin (and salicylate), diazepam and Phenol Red. An attempt to correlate this partial binding model for serum albumin with other models in the literature is made.

scholarly journals Octanoate binding to the indole- and benzodiazepine-binding region of human serum albumin

1991 ◽  
Vol 273 (3) ◽  
pp. 641-644 ◽  
Author(s):  
U Kragh-Hansen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Equilibrium Dialysis ◽  
Affinity Binding ◽  
Experimental Conditions ◽  
High Affinity Binding ◽  
Molar Ratios ◽  
High Affinity ◽  
High Affinity Binding Site

Binding of L-tryptophan, diazepam and octanoate to defatted human serum albumin was studied at pH 7.0 by equilibrium dialysis at low ligand/protein molar ratios. L-Tryptophan binding takes place at only one site of the protein with an association constant of 4.4 x 10(4) M-1. Under the present experimental conditions, binding of diazepam and octanoate could be accounted for by high-affinity binding alone with primary association constants of 3.8 x 10(5) M-1 and 1.6 x 10(6) M-1 respectively. During the simultaneous presence of L-tryptophan plus octanoate or diazepam plus octanoate, pronounced mutual reductions in binding were observed. Analysis of the data suggests that the reductions in binding represent competition for a common high-affinity binding site. Thus a region seems to exist that is capable of binding one molecule of these diverse ligands with a high affinity. The location of this region within the albumin molecule is discussed.

scholarly journals Biological characteristics of two lysines on human serum albumin in the high-affinity binding of 4Z,15Z-bilirubin-IXα revealed by phage display

FEBS Journal ◽  
2011 ◽  
Vol 278 (21) ◽  
pp. 4100-4111 ◽  
Author(s):  
Ai Minomo ◽  
Yu Ishima ◽  
Ulrich Kragh-Hansen ◽  
Victor T. G. Chuang ◽  
Makiyo Uchida ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Phage Display ◽  
Human Serum ◽  
Biological Characteristics ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity

Development of DNA Nanostructures for High-Affinity Binding to Human Serum Albumin

2017 ◽  
Vol 139 (21) ◽  
pp. 7355-7362 ◽  
Author(s):  
Aurélie Lacroix ◽  
Thomas G. W. Edwardson ◽  
Mark A. Hancock ◽  
Michael D. Dore ◽  
Hanadi F. Sleiman
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Affinity Binding ◽  
Dna Nanostructures ◽  
High Affinity Binding ◽  
High Affinity

scholarly journals Characterization of Ca2+ interactions with matrix metallopeptidase-12: implications for matrix metallopeptidase regulation

2006 ◽  
Vol 398 (3) ◽  
pp. 393-398 ◽  
Author(s):  
Thomas Gossas ◽  
U. Helena Danielson
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Calcium Binding ◽  
Three Dimensional ◽  
Zinc Ion ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity ◽  
High Affinity Binding Site ◽  
Matrix Metallopeptidase

Matrix metallopeptidase-12 (MMP-12) binds three calcium ions and a zinc ion, in addition to the catalytic zinc ion. These ions are thought to have a structural role, stabilizing the active conformation of the enzyme. To characterize the importance of Ca2+ binding for MMP-12 activity and the properties of the different Ca2+ sites, the activity as a function of [Ca2+] and the effect of pH was investigated. The enzymatic activity was directly correlated to calcium binding and a Langmuir isotherm for three binding sites described the activity as a function of [Ca2+]. The affinities for two of the binding sites were quantified at several pH values. At pH 7.5, the KD was 0.1 mM for the high-affinity binding site, 5 mM for the intermediate-affinity binding site and >100 mM for the low-affinity binding site. For all three sites, the affinity for calcium decreased with reduced pH, in accordance with the loss of interactions upon protonation of the calcium-co-ordinating aspartate and glutamate carboxylates at acidic pH. The pKa values of the calcium binding sites with the highest and intermediate affinities were determined to be 4.3 and 6.5 respectively. Optimal pH for catalysis was above 7.5. The low-, intermediate- and high-affinity binding sites were assigned on the basis of analysis of three-dimensional-structures of MMP-12. The strong correlation between MMP-12 activity and calcium binding for the physiologically relevant [Ca2+] and pH ranges studied suggest that Ca2+ may be involved in controlling the activity of MMP-12.

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