MECHANISM BY WHICH WARFARIN BINDS TO HUMAN-SERUM ALBUMIN - STOPPED-FLOW KINETIC-EXPERIMENTS WITH 2 LARGE FRAGMENTS OF ALBUMIN
MECHANISM BY WHICH WARFARIN BINDS TO HUMAN-SERUM ALBUMIN - STOPPED-FLOW KINETIC-EXPERIMENTS WITH 2 LARGE FRAGMENTS OF ALBUMIN
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DOI：
10.1016/0006-2952(89)90497-8
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发表时间：
1989-06-15
影响因子：
5.8
通讯作者：
JANSSEN, LHM
中科院分区：
文献类型：
--
作者：
BOS, OJM;FISCHER, MJE;JANSSEN, LHM
为了获得有关华法林在分子水平上与人血清白蛋白结合过程的动力学信息，我们对白蛋白以及白蛋白的大胃蛋白酶片段（残基1-387）和大胰蛋白酶片段（残基198-585）进行了停流动力学实验。从这些实验中可以得出结论，华法林和蛋白质之间的第一次相互作用几乎肯定是扩散控制的，并且取决于反应物的净电荷。结合过程的下一步包括形成活化的华法林-蛋白质复合物，然后形成最终的复合物。华法林-白蛋白复合物的形成比华法林-片段复合物更慢，因为白蛋白结构在空间上阻碍了这种形成。我们认为白蛋白不太可能具有扁椭圆体结构;它更可能具有U形结构，其中结构域彼此接触。如果这个假设是正确的，那么这表明这些域并不是彼此独立地起作用的。活化的华法林-白蛋白复合物的形成还受到白蛋白分子的构象状态（即N-B转变）的影响。讨论了这种N-B过渡在白蛋白介导的药物通过细胞膜转运中的可能作用。
In order to obtain information about the kinetics of the process by which warfarin binds to human serum albumin at a molecular level, we performed stopped-flow kinetic experiments on albumin and on a large peptic fragment (residues 1-387) and a large tryptic fragment (residues 198-585) of albumin. From these experiments it can be concluded that the first interaction between warfarin and the proteins is almost certainly diffusion-controlled and is dependent on the net charges of the reactants. The next step in the binding process involves the formation of an activated warfarin-protein complex, whereafter the final complex is formed. The warfarin-albumin complex forms more slowly than the warfarin-fragment complexes, because the formation is sterically hindered by the albumin structure. We think it very unlikely that albumin has an oblate ellipsoid structure; it is much more likely to have a U-shaped structure, where the domains make contact with each other. If this hypothesis is correct, then this indicates that the domains do not act independently of each other. The formation of the activated warfarin-albumin complex is further influenced by the conformational state of the albumin molecule, i.e. the N-B transition. The possible role of this N-B transition in albumin-mediated transport of drugs through cellular membranes is discussed.