溶液中多肽链局部构象的小角X射线散射函数的推导。

Derivation of the small-angle x-ray scattering functions for local conformations of polypeptide chains in solution.

作者信息

Muroga Y

机构信息

Department of Applied Chemistry, School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.

出版信息

Biopolymers. 2001 Oct 15;59(5):320-9. doi: 10.1002/1097-0282(20011015)59:5<320::AID-BIP1029>3.0.CO;2-#.

DOI:10.1002/1097-0282(20011015)59:5<320::AID-BIP1029>3.0.CO;2-#

PMID:11514935

Abstract

The small-angle x-ray scattering (SAXS) functions are analytically derived for both the randomly coiled and helical local conformations of a polypeptide chain in solution. The resulting scattering functions for helices of various types are characterized by a maximum in the range of scattering-vector corresponding to Bragg spacings of 3-5 A, whereas the random-coil function has no maximum. This result is compatible with the extant SAXS data for partially neutralized poly(L-glutamic acid) and poly(L-lysine) in aqueous solutions. Comparison of the SAXS data with the calculated scattering functions shows that helical structures in both polypeptide chains are of the 3.6(13)-helix (alpha-helix) rather than 3.0(10)-type.

摘要

针对溶液中多肽链的无规卷曲和螺旋局部构象，通过解析方法推导了小角X射线散射（SAXS）函数。所得各种类型螺旋的散射函数在散射矢量范围内存在一个最大值，该范围对应于3 - 5 Å的布拉格间距，而无规卷曲函数则没有最大值。这一结果与水溶液中部分中和的聚（L - 谷氨酸）和聚（L - 赖氨酸）现有的SAXS数据相符。将SAXS数据与计算得到的散射函数进行比较表明，两条多肽链中的螺旋结构均为3.6(13)-螺旋（α-螺旋），而非3.0(10)-型。