STEREOCHEMISTRY OF THE N-GLYCOSYLATION SITES IN GLYCOPROTEINS
STEREOCHEMISTRY OF THE N-GLYCOSYLATION SITES IN GLYCOPROTEINS
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DOI：
10.1093/protein/8.7.699
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发表时间：
1995-07-01
期刊：
影响因子：
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通讯作者：
PEREZ, S
中科院分区：
文献类型：
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作者：
IMBERTY, A;PEREZ, S
本文分析了结晶N-糖蛋白中N-糖苷键的立体化学特征。通过对Brookhaven蛋白质数据库中26种糖蛋白的44个不同糖基化位点的统计分析，提出了GlcNAc部分的平均标准几何构型，沿着提出了其构象行为的合理化。基于分子力学计算分析了观察到的构象的分布，Asn侧链的旋转异构体分布与在非糖基化结构上观察到的一致，并且它与从NMR测量收集的柔性构象的模式一致。在表征蛋白质-聚糖相互作用时，还发现聚糖的两亲性部分与周围的一些芳族或至少疏水性氨基酸残基之间的堆叠。当观察糖基化肽的二级结构时，只有25%的糖基化位点对应于Asn位于β-转角顶部的情况，存在其它类型的二级结构，其满足聚糖暴露在蛋白质表面的空间要求。这些数据可以与最新的肽构象的研究，这将是糖基化所需的。
The stereochemical features displayed by the N-glycosidic linkage in crystalline N-linked glycoproteins are analyzed, From the statistical analysis of 44 different glycosylation sites belonging to 26 glycoproteins of the Brookhaven Protein Data Bank, a mean standard geometry for the GlcNAc moiety, along with a rationalization of its conformational behavior, can be proposed, As for the glycopeptide linkage, the distribution of observed conformations has been analyzed on the basis of molecular mechanics calculations, The rotamer distribution of the Asn side chains conforms to that observed on non-glycosylated structures, and it agrees with the pattern of flexible conformations gathered from NMR measurements, In characterizing the protein-glycan interactions, some hydrogen bonds occur, Stacking between the amphiphilic moiety of the glycan and some surrounding aromatic, or at least hydrophobic, amino acid residues is also found, When looking at the secondary structure of the glycosylated peptide, only 25% of the glycosylation sites correspond to situations where Asn is located at the top of a beta-turn, other types of secondary structure exist which fulfil the spatial requirement of having the glycan exposed at the surface of the protein. These data can be compared with the most recent studies on the peptide conformation which would be required for glycosylation.