The Implications of (2<i>S</i>,4<i>S</i>)-Hydroxyproline 4-<i>O</i>-Glycosylation for Prolyl Amide Isomerization
作者:Neil W. Owens、Adrian Lee、Kirk Marat、Frank Schweizer
DOI:10.1002/chem.200900844
日期:2009.10.12
delineated by the proline sidechain. The enthalpic contributions to the stabilization of the trans amideisomer may be due to disruption of intramolecular interactions present in hyp; the change in enthalpy is balanced by a decrease in entropy incurred upon glycosylation. Because the different stereoisomers—Hyp and hyp—project the O‐linked carbohydrates in opposite spatial orientations, these glycosylated
Development of a simple leaving group for the gold-catalysed glycosylation has been achieved.
已经实现了为金催化糖基化开发简单的脱离基团。
Large-Scale Chemical and Enzymatic Synthesis of a<b>
<i>Clostridium difficile</i>
</b>Toxin A Binding Trisaccharide
作者:R. Murray Ratcliffe、Monica M. Palcic、Vivekanand P. Kamath、Robert E. Yeske、Jonathan M. Gregson、Ying R. Fang
DOI:10.1055/s-2004-831188
日期:——
Trisaccharide 1, 8-methoxycarbonyloctyl-O-(α-D-galactopyranosyl)-(1→3)-(β-D-galactopyranosyl)-(1→4)-β-D-glucopyranoside, linked to a solid support can be used to remove Clostridium difficile toxin A from the intestinal tract. Therefore, multi-gram chemical and enzymatic synthesis of the toxin binding trisaccharide 1 from 8-methoxycarbonyloctyl β-lactoside disaccharide 2 were explored. Chemical conversion
Effects of Glycosylation of (2<i>S</i>,4<i>R</i>)-4-Hydroxyproline on the Conformation, Kinetics, and Thermodynamics of Prolyl Amide Isomerization
作者:Neil W. Owens、Craig Braun、Joe D. O'Neil、Kirk Marat、Frank Schweizer
DOI:10.1021/ja073488d
日期:2007.9.1
the peptide backbone. As a consequence, there is a reduction in the energy difference between the prolyl amide cis and trans isomers, making them nearly isoenergetic; this leads to higher cis N-terminal amide content relative to the other amino acids. Moreover, the isomerization of the prolyl amide bond has been shown to be the ratedetermining step in the folding pathways of many peptides and proteins
Hyp-糖基化对肽骨架构象的构象影响。Hyp 和脯氨酸 (Pro) 在蛋白氨基酸中是独一无二的,因为它们的特点是 o 二面角的有限旋转(图 1),因为它们的侧链与肽主链融合。因此,脯氨酰胺顺式和反式异构体之间的能量差减小,使它们几乎等能;这导致相对于其他氨基酸更高的顺式 N 端酰胺含量。此外,脯氨酰胺键的异构化已被证明是许多肽和蛋白质折叠途径中的速率决定步骤。4 在本文中,我们描述了 Hyp 的半乳糖基化对脯氨酰 N 端酰胺异构化的构象以及热力学和动力学的影响。