Cisplatin binding sites on human albumin
Cisplatin binding sites on human albumin
复制标题
DOI：
10.1074/jbc.273.24.14721
复制
发表时间：
1998-06-12
影响因子：
4.8
通讯作者：
Sadler, PJ
中科院分区：
文献类型：
--
作者：
Ivanov, AI;Christodoulou, J;Sadler, PJ
顺铂 (cis-[PtCl2(NH3)(2)]) 与白蛋白的反应被认为在这种抗癌药物的代谢中发挥重要作用。这里通过（i）用 N-15 标记顺铂并使用二维 H-1,N-15 NMR 光谱，（ii）天然人血清白蛋白与重组人白蛋白（较高的同质性和 SH 含量）的比较，（iii）Cys、Met 和 His 残基的化学修饰，（iv）结合铂与硫脲的反应，以及（v）凝胶过滤色谱法进行研究。与以前的报道相反，表明主要含硫结合位点包括 Met 而不是 Cys-34，以及 S,N 大螯合物形式的 N 配体。还观察到涉及其他 Met 残基和 Cys-34 的其他单功能加合物。在顺铂与白蛋白反应的后期，由于Met硫的强烈反式影响，发生NH3的释放，削弱了Pt-NH3键，并观察到蛋白质交联。讨论了这些发现对顺铂-白蛋白复合物的生物活性的影响。
Reactions of cisplatin (cis-[PtCl2(NH3)(2)]) with albumin are thought to play an important role in the metabolism of this anticancer drug. They are investigated here via (i) labeling of cisplatin with N-15 and use of two-dimensional H-1,N-15 NMR spectroscopy, (ii) comparison of natural human serum albumin with recombinant human albumin (higher homogeneity and SH content), (iii) chemical modification of Cys, Met, and His residues, (iv) reactions of bound platinum with thiourea, and (v) gel filtration chromatography, In contrast to previous reports, it is shown that the major sulfur-containing binding site involves Met and not Cys-34, and also a N ligand, in the form of an S,N macrochelate. Additional monofunctional adducts involving other Met residues and Cys-34 are also observed. During the later stages of reactions of cisplatin with albumin, release of NH3 occurs due to the strong trans influence of Met sulfur, which weakens the Pt-NH3 bonds, and protein cross-linking is observed. The consequences of these findings for the biological activity of cisplatin-albumin complexes are discussed.