ATOMIC CO-ORDINATES FRO AN ALPHA-HELIX - REFINEMENT OF CRYSTAL STRUCTURE OF ALPHA-POLY-L-ALANINE
ATOMIC CO-ORDINATES FRO AN ALPHA-HELIX - REFINEMENT OF CRYSTAL STRUCTURE OF ALPHA-POLY-L-ALANINE
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DOI：
10.1016/0022-2836(66)90105-7
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发表时间：
1966-01-01
影响因子：
5.6
通讯作者：
WONACOTT, AJ
中科院分区：
文献类型：
--
作者：
ARNOTT, S;WONACOTT, AJ
重新测量了[α] -聚-L-丙氨酸的X射线衍射图。强度数据，更高的精度和分辨率比以前使用的，已被包括在一个自动化的过程中，用于精炼聚合物晶体结构。确定了分子堆积和构象参数的最佳值。这一改进将Elliott和Malcolm（1959）提出的晶体结构置于定量基础上。我们在晶体和原子参数方面的改进与他们的建议是同类的，但在数量上不同。这些实验结果有力地支持了从简单的能量考虑的构象和包装的预测。最近采用的标准蛋白质构象角[phi]，[psi]，[omega]在此细化中不是明确的变量，但可以从细化的分子参数分别计算为113[degree] 7[image]，136[degree] 19[image]，-l[degree] 0[image]。
X-Ray diffraction patterns from [alpha] -poly-L-alanine have been remeasured. Intensity data, of greater accuracy and resolution than previously used, have been included in an automatic process for refining polymer crystal structures. Optimum values of the molecular packing and conformational parameters have been determined. The refinement places on a quantitative basis the crystal structure proposals of Elliott and Malcolm (1959). Our improvements in the crystal and atomic parameters are of the same kind but different in magnitude from their suggestions. Predictions of conformation and packing from simple energy considerations are strongly supported by these experimental results. The recently adopted standard protein conformation angles [phi], [psi], [omega] were not explicit variables in this refinement but could be calculated from the refined molecular parameters to be respectively 113[degree] 7[image], 136[degree] 19[image], -l[degree] 0[image].