Conformational dynamics of the carboxylic ionophore lasalocid A underlying cation complexation-decomplexation and membrane transport.
Conformational dynamics of the carboxylic ionophore lasalocid A underlying cation complexation-decomplexation and membrane transport.
复制标题
羧基离子载体拉沙里菌素的构象动力学潜在的阳离子络合-解络和膜运输。
DOI：
10.1021/bi00265a035
复制
发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Pressman,BC
中科院分区：
文献类型：
--
作者：
Painter,GR;Pollack,R;Pressman,BC
乔治河画家，* 罗纳德波拉克和伯顿C。Pressman摘要：利用圆二色性（CD）和计算机生成的分子模型研究了拉沙洛西A在一系列极性梯度溶剂中的构象动力学。在高极性溶剂中，未络合的阴离子载体呈现非环状构象，使固有分子应变能最小化。在这种状态下，碳骨架中的配位氧的偶极子和末端羧酸酯通过高度的溶剂缔合而稳定。随着溶剂极性的降低，动态构象平衡逐渐向环状构象转移，在低极性下占主导地位。环化通过围绕三个碳-碳铰链键旋转进行。所产生的主链扭曲引入了扭转应变，该扭转应变在低极性下被通过分子内氢键键合获得的静电稳定化抵消。形成
George R. Painter,* Ronald Pollack, and Berton C. Pressman abstract: The conformational dynamics of lasalocid A have been studied in a series of solvents of graded polarity by means of circulardichroism (CD) and computer-generated molecular models. In high polarity solvents, the uncomplexed anionic ionophore assumes an acyclic conformation minimizing in-trinsic molecular strain energy. In this state, the dipoles of the liganding oxygens in the carbon backbone and the terminal carboxylate are stabilized by a high degree of solvent asso-ciation. As the solvent polarity decreases, the dynamic con-formational equilibrium progressively shifts toward a cyclic conformation which predominates at low polarity. Cyclization proceeds by rotation about three carbon-carbon hingebonds. The resulting twist of the backbone introduces torsional strain which is offset at low polarity by electrostatic stabilization gained through intramolecular hydrogen bonding. Formation