(14) 通过固态 NMR 光谱研究酰胺氮和肽二级结构的 14N 四极耦合。

(14)N quadrupolar coupling of amide nitrogen and Peptide secondary structure as studied by solid-state NMR spectroscopy.

机构信息

Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.

出版信息

J Am Chem Soc. 2010 Mar 31;132(12):4290-4. doi: 10.1021/ja909931j.

DOI:10.1021/ja909931j

PMID:20218586

Abstract

To establish a relationship between the secondary structure of a peptide and the quadrupolar coupling of its amide (14)N, we examined (14)N quadrupolar couplings for eight different polypeptide samples, each of whose secondary structure (alpha-helix or beta-sheet) is known. The (14)N quadrupolar coupling is estimated from indirect observation of a (14)N overtone resonance under magic-angle spinning. From the observed indirect (14)N overtone spectra and calculated (14)N quadrupolar couplings for model molecules by using ab initio calculation (Gaussian03), it is shown that the quadrupolar coupling for the alpha-helix is larger than that for the beta-sheet by a few 100 kHz irrespective of the kind of amino acid residues examined (Ala, Val, Leu).

摘要

为了建立肽的二级结构与其酰胺（14）N 的四极耦合之间的关系，我们检查了 8 种不同多肽样品的（14）N 四极耦合，这些样品的二级结构（α-螺旋或β-折叠）是已知的。（14）N 四极耦合是通过在魔角旋转下间接观察（14）N 泛频共振来估计的。从观察到的间接（14）N 泛频光谱和通过使用从头算计算（Gaussian03）对模型分子计算的（14）N 四极耦合，表明α-螺旋的四极耦合比β-折叠大几个 100 kHz，而与所检查的氨基酸残基的种类（Ala、Val、Leu）无关。