Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, pr. Torez 44, 194223 St. Petersburg, Russia.
St. Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia.
Int J Mol Sci. 2024 Oct 27;25(21):11543. doi: 10.3390/ijms252111543.
Data are accumulating on the hydrolytic activity of serum albumin towards esters and organophosphates. Previously, with the help of the technology of proton nuclear magnetic resonance (H NMR) spectroscopy, we observed the yield of acetate in the solution of bovine serum albumin and -nitrophenyl acetate (NPA). Thus, we showed that albumin possesses true esterase activity towards NPA. Then, using the methods of molecular docking and molecular dynamics, we established site Sudlow I as the catalytic center of true esterase activity of albumin. In the present work, to expand our understanding of the molecular mechanisms of albumin pseudoesterase and true esterase activity, we investigated-in experiments in vitro and in silico-the interaction of anticoagulant warfarin (WRF, specific ligand of site Sudlow I) and benzodiazepine diazepam (DIA, specific ligand of site Sudlow II) with albumins of different species, and determined how the binding of WRF and DIA affects the hydrolysis of NPA by albumin. It was found that the characteristics of the binding modes of WRF in site Sudlow I and DIA in site Sudlow II of human (HSA), bovine (BSA), and rat (RSA) albumins have species differences, which are more pronounced for site Sudlow I compared to site Sudlow II, and less pronounced between HSA and RSA compared to BSA. WRF competitively inhibits true esterase activity of site Sudlow I towards NPA and does not affect the functioning of site Sudlow II. Diazepam can slow down true esterase activity of site Sudlow I in noncompetitive manner. It was concluded that site Sudlow I is more receptive to allosteric modulation compared to site Sudlow II.
关于血清白蛋白对酯类和有机磷的水解活性，相关数据正在不断积累。此前，我们借助质子核磁共振（H NMR）光谱技术，观察了牛血清白蛋白与 - 硝基苯乙酸酯（NPA）溶液中乙酸盐的生成情况。由此，我们证明白蛋白对 NPA 具有真正的酯酶活性。随后，我们采用分子对接和分子动力学的方法，确定了 Sudlow I 位点是白蛋白真正酯酶活性的催化中心。在本工作中，为了进一步了解白蛋白假酯酶和真正酯酶活性的分子机制，我们在体外和计算机模拟实验中，研究了抗凝剂华法林（WRF，Sudlow I 位点的特异性配体）和苯二氮䓬类药物地西泮（DIA，Sudlow II 位点的特异性配体）与不同物种白蛋白的相互作用，并确定了 WRF 和 DIA 的结合如何影响白蛋白对 NPA 的水解。结果发现，WRF 在人（HSA）、牛（BSA）和大鼠（RSA）白蛋白的 Sudlow I 位点、DIA 在 Sudlow II 位点的结合模式特征存在种属差异，且在 Sudlow I 位点比在 Sudlow II 位点更为显著，而在 HSA 和 RSA 之间比在 BSA 之间的差异较小。WRF 竞争性抑制 Sudlow I 位点对 NPA 的真正酯酶活性，且不影响 Sudlow II 位点的功能。地西泮可非竞争性地减缓 Sudlow I 位点的真正酯酶活性。综上，与 Sudlow II 位点相比，Sudlow I 位点对别构调节更敏感。
