Effects of drug binding on the esterase-like activity of human serum albumin. VI. Reaction with di-p-nitrophenyl adipate.
作者:YUKIHISA KURONO、HITOMI SUGIURA、KEN IKEDA
DOI:10.1248/cpb.33.3966
日期:——
The binding of R type drugs, which have high affinity to a site (R site) near the tyrosine-411 residue, remarkably accelerated the reaction of di-p-nitrophenyl adipate (D) with human serum albumin (HSA). The reaction was investigated kinetically at various pHs and 25°C. The reaction in the presence of an excess of HSA over D proceeded in two steps. The pH-profiles for both rate constants were sigmoidal, indicating the participation of two tyrosine residues having pKa values of about 9.3 in the reactions. The two residues of HSA involved seem to be separated by a distance corresponding to the length of the adipoyl group.
R 型药物与酪氨酸-411 残基附近的一个位点(R 位点)具有高亲和力,它们的结合明显加速了己二酸二对硝基苯酯(D)与人血清白蛋白(HSA)的反应。在不同的 pH 值和 25°C 温度条件下对该反应进行了动力学研究。在 HSA 超过 D 的情况下,反应分两步进行。两个速率常数的 pH 值曲线均为正弦曲线,表明两个 pKa 值约为 9.3 的酪氨酸残基参与了反应。参与反应的两个 HSA 残基之间的距离与己二酰基团的长度相当。