Fiori W R, Lundberg K M, Millhauser G L
Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064, USA.
Nat Struct Biol. 1994 Jun;1(6):374-7. doi: 10.1038/nsb0694-374.
Arginine is a stabilizing element in both thermophilic and low molecular weight proteins. Similarly Lys+-->Arg+ substitutions increase the helix content of designed helical peptides. Here we explore this 'arginine effect' by examining how Lys+-->Arg+ substitutions influence the 3(10)-helix-->alpha-helix equilibrium in the helical peptide Ac-(AAAAK)3A-NH2. The unsubstituted sequence contains a significant amount of 3(10)-helix, however, single Lys+-->Arg+ substitutions shift the peptide conformation toward alpha-helix in a position-dependent fashion. The single substitution closest to the carboxy terminus induces the largest conformational change at the helix amino terminus. These findings suggest that a single strategically-placed arginine can exert long range control on helix structure.
精氨酸是嗜热蛋白和低分子量蛋白中的一种稳定元素。同样地，赖氨酸（Lys）向精氨酸（Arg）的取代增加了设计的螺旋肽的螺旋含量。在此，我们通过研究赖氨酸向精氨酸的取代如何影响螺旋肽Ac-(AAAAK)3A-NH2中3(10)-螺旋向α-螺旋的平衡，来探究这种“精氨酸效应”。未被取代的序列含有大量的3(10)-螺旋，然而，单个赖氨酸向精氨酸的取代会以位置依赖的方式使肽构象向α-螺旋转变。最靠近羧基末端的单个取代在螺旋氨基末端诱导出最大的构象变化。这些发现表明，单个经过策略性定位的精氨酸可以对螺旋结构施加远程控制。
