Effects of Glycosylation of (2S,4R)-4-Hydroxyproline on the Conformation, Kinetics, and Thermodynamics of Prolyl Amide Isomerization

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• 作者：Neil W. Owens ; Craig Braun ; Joe D. O'Neil ; Kirk Marat ; Frank Schweizer
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：September 26, 2007
• 年：2007
• 卷：129
• 期：38
• 页码：11670 - 11671
• 全文大小：34K
• 年卷期：v.129,no.38(September 26, 2007)
• ISSN：1520-5126

文摘

Glycosylation (galactosylation) of (2S,4R)-4-hydroxyproline (Hyp) in the peptide mimic N-acetyl-Hyp-N'-methylamide does not mediate the isomer equilibrium nor the rate of isomerization between the cis- and trans-prolyl amides in water. However, glycosylation of Hyp results in a downfield shift (6.5-8 ppm) of the C atom of proline that is consistent with an enhanced inductive effect. Moreover, NOE experiments on the -and -linked glycosylated AcHypNHMe amides indicate proximity between the galactose and pyrrolidine rings. This study strongly suggests that glycosylation of Hyp will have important implications on peptide backbone conformation