Origins of Helix-Coil Switching in a Light-Sensitive Peptide

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• 作者：Darcy C. Burns ; Daniel G. Flint ; Janet R. Kumita ; Howard J. Feldman ; Luis Serrano ; Zhihua Zhang ; Oliver S. Smart ; and G. Andrew Woolley
• 刊名：Biochemistry
• 出版年：2004
• 出版时间：December 14, 2004
• 年：2004
• 卷：43
• 期：49
• 页码：15329 - 15338
• 全文大小：339K
• 年卷期：v.43,no.49(December 14, 2004)
• ISSN：1520-4995

文摘

Intramolecular cross-linking of peptides by the light-sensitive compound diiodoacetamideazobenzene has been shown to permit reversible photocontrol of the helix-coil transition. Cross-linkingbetween Cys residues spaced at i and i + 7 positions with the trans form of the linker was found toproduce a decreased helix content compared to that of the non-cross-linked peptide. Photoisomerizationto the cis form of the linker led to substantially higher helix content than in the non-cross-linked peptide.Detailed conformational analysis of the system leads to the conclusion that photocontrol of helix contentdoes not involve specific interactions between the linker and the peptide. Instead, the change in peptidehelix content caused by photoisomerization can be predicted by comparing the length ranges of the cisand trans forms of the linker with the expected distance distribution of the Cys attachment points in theintrinsic conformational ensemble of the peptide. The analysis presented here should help to guide theuse of these and related linkers for the conformational control of a variety of peptide and protein systems.