Role of modified glutamic acid in the helical structure of conantokin‐T

FEBS Letters

Lin, C.H²  Hsu, K.S³  Lyu, P.C²  King, D.S¹  Chen, C.S² 

[1] Howard Hughes Medical Institute, 401 Barker Hall, University of California, Berkeley, CA 94720-3202, USA;Department of Life Sciences, National Tsing Hua University, Hsin-chu 30043, Taiwan;Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan 701, Taiwan

关键词: Conantokin-T;    NMDA receptor;    γ-Carboxyglutamic acid;    Helix;    Circular dichroism;    NMR;   

DOI  :  10.1016/S0014-5793(97)00354-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Circular dichroism (CD) and 2-dimensional NMR were used to study the solution conformation of conantokin-T (Con-T), a small peptide toxin found in the venom of fish-hunting cone snails, and its Glu-substituted analog. Con-T lacks disulfide bonds but contains many γ-carboxyglutamic acids (Gla), a post-translationally modified residue. Our results show that Con-T adopts an α-helical conformation in aqueous solution even in the absence of calcium. Glu replacements diminish both helicity and function of Con-T. The helical content of Con-T is higher than most natural helical peptides of this length in aqueous solution. The sequence of this small toxin incorporates several known elements that stabilize α-helical structure in peptides. Gla residues form several salt bridges that stabilize helical conformation of Con-T.

【 授权许可】

Unknown