RELATIONS BETWEEN HIGH-AFFINITY BINDING-SITES OF MARKERS FOR BINDING REGIONS ON HUMAN-SERUM ALBUMIN
RELATIONS BETWEEN HIGH-AFFINITY BINDING-SITES OF MARKERS FOR BINDING REGIONS ON HUMAN-SERUM ALBUMIN
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DOI：
10.1042/bj2250629
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发表时间：
1985-01-01
影响因子：
4.1
通讯作者：
KRAGHHANSEN, U
中科院分区：
文献类型：
--
作者：
KRAGHHANSEN, U
在pH 7.0下，研究了华法林、洋地黄毒苷、地西泮、水杨酸盐和酚红单独或以不同对组合与脱脂人血清白蛋白在配体/蛋白摩尔比< 1：1时的结合。通过超滤测定结合。为了加强结果，使用平衡透析重复了一些实验。无论使用哪种方法，所有配体均与1个高亲和力结合位点结合，结合常数范围为104-106 M-1。以下配体对的高亲和力结合独立地发生：华法林-酚红、华法林-地西泮、华法林-地高辛和洋地黄毒苷-地西泮。华法林和水杨酸盐的同时结合导致彼此结合的相互减少，同时结合洋地黄毒苷和酚红。这两种效应都可以用耦合常数来解释。耦合常数是影响初级缔合常数的因子;在这些反协同性的例子中，该因子的值在0和1之间。在第一个例子中，它被计算为0.8，在后者中为0.5。洋地黄毒苷和水杨酸被发现竞争一个共同的高亲和力结合位点。目前的研究结果支持华法林，洋地黄毒苷（和水杨酸盐），地西泮和酚红的4个独立的主要结合位点的建议。试图将此血清白蛋白的部分结合模型与文献中的其他模型相关联。
The 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 < 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 1 high-affinity binding site with an association constant in the range 104-106 M-1. High-affinity binding of the following pair of ligands took place independently: warfarin-Phenol Red, warfarin-diazepam, warfarin-digoxin 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. Digitoxin and salicylate were found to compete for a common high-affinity binding site. The present findings support the proposal of 4 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.