去污剂胶束对视蛋白与11-顺式视黄醛重组反应的影响。

Effects of detergent micelles on the recombination reaction of opsin and 11-cis-retinal.

作者信息

McCaslin D R, Tanford C

出版信息

Biochemistry. 1981 Sep 1;20(18):5207-12. doi: 10.1021/bi00521a017.

Abstract

When detergent-solubilized proteins interact with hydrophobic or amphiphilic molecules in the presence of detergent micelles, the solubility of the latter species in the micelles must be included in both thermodynamic and kinetic treatments. In this paper, we derive equations which describe the distribution of species present at equilibrium for a system in which a detergent-solubilized protein binds a hydrophobic (or amphiphilic) ligand. We have applied the formalism developed in this paper to the reaction describing the formation of rhodopsin from its apoprotein and 11-cis-retinal. Qualitatively, the results demonstrate that a significant portion of the observed decrease in the extent of recombination for rhodopsin solubilized in either sodium cholate or Tween 80 may be attributed to the partition of retinal into detergent micelles and that a detergent-induced protein denaturation need not be invoked to explain the data. We also discuss results for rhodopsin solubilized in a nonionic detergent (octaethylene glycol n-dodecyl ether) in which the detergent is clearly causing irreversible loss of the capability to recombine with 11-cis-retinal.

摘要

当用去污剂增溶的蛋白质在去污剂胶束存在的情况下与疏水或两亲性分子相互作用时，后一类物质在胶束中的溶解度必须包含在热力学和动力学处理中。在本文中，我们推导了一些方程，这些方程描述了一个用去污剂增溶的蛋白质结合疏水（或两亲性）配体的系统在平衡时存在的各种物质的分布情况。我们已将本文所建立的形式体系应用于描述视紫红质由其脱辅基蛋白和11-顺式视黄醛形成的反应。定性地说，结果表明，观察到的溶解在胆酸钠或吐温80中的视紫红质重组程度下降的很大一部分可能归因于视黄醛在去污剂胶束中的分配，而且无需用去污剂诱导的蛋白质变性来解释这些数据。我们还讨论了溶解在非离子去污剂（八甘醇正十二烷基醚）中的视紫红质的结果，在这种情况下，去污剂显然导致了与11-顺式视黄醛重组能力的不可逆丧失。