溶液 NMR 证据表明功能或晶体学不对称同源二聚体存在对称性。

Solution NMR evidence for symmetry in functionally or crystallographically asymmetric homodimers.

机构信息

Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.

出版信息

J Am Chem Soc. 2011 Dec 14;133(49):19578-81. doi: 10.1021/ja206967d. Epub 2011 Nov 14.

DOI:10.1021/ja206967d

PMID:22074452

Abstract

A recurrent theme of many structural studies of homo-oligomeric protein systems is concerned with verification that the conformation observed in a crystal represents the functionally relevant structure. An asymmetric conformation adopted by two chemically identical subunits in homo-oligomers can represent an intrinsic property of a protein or be an artifact induced by crystal packing forces. Solution NMR studies can distinguish between these two possibilities. Using methyl-based NMR spectroscopy, we provide evidence for symmetry in the absence of ligands in several homodimeric proteins that are either asymmetric functionally and/or adopt different conformations of the two subunits in available X-ray structures.

摘要

许多同聚体蛋白系统结构研究的一个反复出现的主题是关注所观察到的晶体构象是否代表功能相关的结构。同聚体中两个化学上相同的亚基所采用的非对称构象可以代表蛋白质的固有特性，也可以是晶体包装力诱导的假象。溶液 NMR 研究可以区分这两种可能性。我们使用基于甲基的 NMR 光谱学，在没有配体的情况下，为几个同二聚体蛋白质提供了证据，这些蛋白质在功能上是不对称的，或者在现有的 X 射线结构中采用了两个亚基的不同构象。