Dependence of positive binding energies on side chains--a theoretical prediction on the origin of regular ordering for the amino acid residues in the selectivity filter.
Dependence of positive binding energies on side chains--a theoretical prediction on the origin of regular ordering for the amino acid residues in the selectivity filter.
复制标题
DOI：
10.1021/jp074198m
复制
发表时间：
2007-11
期刊：
影响因子：
--
通讯作者：
H. Ai;Chong Zhang;Yun Li;Liang Zhang;Fang Li
中科院分区：
文献类型：
--
作者：
H. Ai;Chong Zhang;Yun Li;Liang Zhang;Fang Li
金属化和质子化二肽的侧链效应，包括GGH（+）M（+）、GAH（+）M（+）、AGH（+）M（+）、AAH（+）M（+）、GWH（+）M（+）、GSH（+）M（+）、GTH（+）M（+）、GFH（+）M（+）、GYH（+）M（+）和GVH（+）M（+）（G =甘氨酸，A =丙氨酸，W =色氨酸，S =丝氨酸，T =苏氨酸，F =苯丙氨酸，V =缬氨酸; M = Li，Na，K）的正结合能，其衍生自M+与羧基氧的相互作用。B3 LYP/6-311++G（**）//B3 LYP/6- 31 G（*）计算结果表明，含侧链的二肽的PBE比不含侧链的（GGH（+）M（+））小得多.一般来说，较大的侧链和较小的M（+）半径将导致较少的PBE的M（+）参与的系统。基于这些二肽模型中PBE对两种阳离子（H（+）和M（+））之间的静电排斥的直接依赖性，可以合理地预期，侧链对静电排斥以及因此对PBE的影响可以提供一个很好的洞察力，在化学物理基础上，当它们在K（+）通道蛋白中形成过滤器时，氨基酸的规则排序的起源（MacKinnon等，Science 1998，280，106）。
The side-chain effects of metalated and protonated dipeptides, including GGH(+)M(+), GAH(+)M(+), AGH(+)M(+), AAH(+)M(+), GWH(+)M(+), GSH(+)M(+), GTH(+)M(+), GFH(+)M(+), GYH(+)M(+), and GVH(+)M(+) (G = glycine, A = alanine, W = tryptophan, S = serine, T = threonine, F = phenylalanine, and V = valine; M = Li, Na, and K), are theoretically explored in this paper on their positive binding energies (PBEs), which are derived from interactions of M+ with the carboxyl oxygen(s). The B3LYP/6-311++G(**)// B3LYP/6-31G(*) calculations suggest that the PBEs of dipeptides with side chain(s) are much smaller than those with no side chain (GGH(+)M(+)). Generally, larger side chains and smaller M(+) radii would lead to fewer PBEs for the M(+) involved systems. On the basis of the direct dependence of PBE on the electrostatic repulsion between two kinds of cations (H(+) and M(+)) in these dipeptide models, it could be reasonably expected that the side-chain effect on the electrostatic repulsion and consequently on the PBEs could offer one good insight, on a chemical-physical basis, into the origin of regular ordering of the amino acids when they form a filter in the K(+) channel protein (MacKinnon, et al. Science 1998, 280, 106).