Template-nucleated alanine-lysine helices are stabilized by position-dependent interactions between the lysine side chain and the helix barrel
Template-nucleated alanine-lysine helices are stabilized by position-dependent interactions between the lysine side chain and the helix barrel
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DOI：
10.1073/pnas.93.9.4025
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发表时间：
1996-04-30
影响因子：
11.1
通讯作者：
Kemp, DS
中科院分区：
文献类型：
--
作者：
Groebke, K;Renold, P;Kemp, DS
已经测定了几个系列富含丙氨酸的肽在水中的螺旋度，这些肽含有单个赖氨酸残基，并且N-末端连接到称为Ac-Hel的螺旋诱导和报告模板（1）。最适合这些肽的性质的丙氨酸的螺旋增长常数（s（Ala）值）在1.01-1.02的范围内，接近Scheraga及其同事报道的值[Wojcik，J.，Altmann，K.- H. & Scheraga，H.A.（1990）Biopolymers 30，121-134]，但显著低于Baldwin及其同事[Chakrabartty，A.，Kortemme，T. & Baldwin，R. L.（1994）Protein Sci. 3，843-852]。通过对Ac-Hel（1）-Ala（n）-Lys-Ala（m）-NH 2和赖氨酸侧链的亚甲基部分被截短的类似物的缀合物的研究，我们发现Ala（n）Lys肽的不寻常的螺旋稳定性主要由赖氨酸侧链与螺旋桶的相互作用控制，并且仅被动地由丙氨酸基质控制。使用H-1 NMR光谱，我们观察到核Overhauser效应crosspeaks一致的质子-质子接触预期这些相互作用。
The helicity in water has been determined for several series of alanine-rich peptides that contain single lysine residues and that are N-terminally linked to a helix-inducing and reporting template termed Ac-Hel(1). The helix-propagating constant for alanine (s(Ala) value) that best fits the properties of these peptides lies in the range of 1.01-1.02, close to the value reported by Scheraga and coworkers [Wojcik, J., Altmann, K.-H. & Scheraga, H.A. (1990) Biopolymers 30, 121-134], but significantly lower than the value assigned by Baldwin and coworkers [Chakrabartty, A., Kortemme, T. & Baldwin, R. L. (1994) Protein Sci. 3, 843-852]. From a study of conjugates Ac-Hel(1)-Ala(n)-Lys-Ala(m)-NH2 and analogs in which the methylene portion of the lysine side chain is truncated, we find that the unusual helical stability of Ala(n)Lys peptides is controlled primarily by interactions of the lysine side chain with the helix barrel and only passively by the alanine matrix. Using H-1 NMR spectroscopy, we observe nuclear Overhauser effect crosspeaks consistent with proton-proton contacts expected for these interactions.