C11/C9 Helices in Crystals of 伪尾 Hybrid Peptides and Switching Structures between Helix Types by Variation in the 伪-Residue

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• 作者：Krishnayan Basuroy ; Vasantham Karuppiah ; Padmanabhan Balaram
• 刊名：Organic Letters
• 出版年：2014
• 出版时间：September 5, 2014
• 年：2014
• 卷：16
• 期：17
• 页码：4614-4617
• 全文大小：321K
• ISSN：1523-7052

文摘

Close-packed helices with mixed hydrogen bond directionality are unprecedented in the structural chemistry of 伪-polypeptides. While NMR studies in solution state provide strong evidence for the occurrence of mixed helices in (尾尾)_n and (伪尾)_n sequences, limited information is currently available in crystals. The peptide structures presented show the occurrence of C₁₁/C₉ helices in (伪尾)_n peptides. Transitions between C₁₁ and C₁₁/C₉ helices are observed upon varying the 伪-amino acid residue.