WATER-INSERTED ALPHA-HELICAL SEGMENTS IMPLICATE REVERSE TURNS AS FOLDING INTERMEDIATES
WATER-INSERTED ALPHA-HELICAL SEGMENTS IMPLICATE REVERSE TURNS AS FOLDING INTERMEDIATES
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DOI：
10.1126/science.2734612
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发表时间：
1989-06-16
期刊：
影响因子：
56.9
通讯作者：
SEKHARUDU, YC
中科院分区：
文献类型：
--
作者：
SUNDARALINGAM, M;SEKHARUDU, YC
与 .alpha 折叠和展开相关的信息。螺旋是从蛋白质结构分析中提取出来的。 .alpha。已发现蛋白质晶体结构中的螺旋是水合的，要么在外部通过水分子与主链羰基氧原子形成氢键，要么在内部通过插入螺旋氢键并在主链羰基氧和酰胺氮原子之间形成氢键桥。水插入的α螺旋片段显示出多种反折构象，例如III型、II型、I型和打开的构象，可以将其视为折叠中间体，其被困在α的折叠-展开过程中。螺旋。自从.alpha。螺旋、大多数匝数和扩展的 .beta。链占据.vphi.、.psi构象空间中的连续区域。二面角，可以为α的折叠-展开过程提出一个合理的路径。水溶液中的螺旋。
Information relevant to the folding and unfolding of .alpha. helices has been extracted from an analysis of protein structures. The .alpha. helices in protein crystal structures have been found to be hydrated, either externally by a water molecule hydrogen bonding to the backbone carbonyl oxygen atom, or internally by inserting into the helix hydrogen bond and forming a hydrogen-bonded bridge between the backbone carbonyl oxygen and the amide nitrogen atoms. The water-inserted .alpha.-helical segments display a variety of reverse-turn conformations, such as type III, type II, type I, and opened out, that can be considered as folding intermediates that are trapped in the folding-unfolding process of .alpha. helices. Since the .alpha. helix, most turns, and the extended .beta. strand occupy contiguous regions in the conformational space of .vphi., .psi. dihedral angles, a plausible pathway can be proposed for the folding-unfolding process of .alpha. helices in aqueous solution.