用于测定竞争性结合的微量量热法。一种精神药物（氯氮卓二钾）对L-色氨酸-人血清白蛋白复合物的作用。

Microcalorimetric method to determine competitive binding. Action of a psychotropic drug (dipotassium chlorazepate) on L-tryptophan . human serum albumin complex.

作者信息

Coassolo P, Briand C, Bourdeaux M, Sari J C

出版信息

Biochim Biophys Acta. 1978 Feb 1;538(3):512-20. doi: 10.1016/0304-4165(78)90412-9.

Abstract

A mathematical treatment and an original microcalorimetric method are developed to verify an eventual competitive binding between any two substances for the same macromolecule. To apply this method, a competitive binding of L-tryptophan and one benzodiazepin (dipotassium chlorazepate) for human serum albumin is perfectly demonstrated. The association constants and the enthalpy variations are equal to 14 000 +/- 2000 M-1 and --6.6 +/- 0.2 kcal/mol for human serum albumin . tryptophan complex and 13 000 +/- 1000 M-1 and --10.0 +/- 0.2 kcal/mol for human serum albumin . chlorazepate complex. In all cases the stoichiometry is equal to one. The binding of tryptophan to human serum albumin is partially stereospecific; the association constant and the enthalpy variation for D-tryptophan complex are equal, respectively, to 1000 +/- 200 M-1 and --2.6 +/- 0.3 kcal/mol.

摘要

开发了一种数学处理方法和一种原创的微量量热法，以验证任意两种物质对同一大分子的最终竞争结合。为应用此方法，完美证明了L-色氨酸与一种苯二氮䓬（氯氮䓬二钾）对人血清白蛋白的竞争结合。人血清白蛋白-色氨酸复合物的缔合常数和焓变分别为14000±2000 M⁻¹和-6.6±0.2 kcal/mol，人血清白蛋白-氯氮䓬复合物的缔合常数和焓变分别为13000±1000 M⁻¹和-10.0±0.2 kcal/mol。在所有情况下，化学计量比均为1。色氨酸与人血清白蛋白的结合具有部分立体特异性；D-色氨酸复合物的缔合常数和焓变分别为1000±200 M⁻¹和-2.6±0.3 kcal/mol。