On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database
On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database
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DOI：
10.1016/s0304-4165(99)00165-8
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发表时间：
1999-12-06
影响因子：
3
通讯作者：
Sharon, N
中科院分区：
文献类型：
--
作者：
Apweiler, R;Hermjakob, H;Sharon, N
SWISS-PROT蛋白质序列数据库目前包含近75000个条目，其中近三分之二包括潜在的N-糖基化共有序列，或序列子，NXS/T（其中X为除脯氨酸外的任何氨基酸），因此可能是糖蛋白。然而，作为糖蛋白提交的蛋白质数量要少得多，为 7942 个，其中 749 个已对其碳水化合物单元的总数和后者与蛋白质的连接位点以及碳水化合物-肽连接基团的性质进行了表征。在这些充分表征的糖蛋白中，约 90% 单独携带 N-连接碳水化合物单元或同时携带 N-和 O-连接碳水化合物单元，连接在 1297 个 N-糖基化位点（每个糖蛋白分子 1.9 个），其余的仅携带 O-糖基化。由于已明确表征的糖蛋白中的序列序列总数为 1968 个，因此它们的占用率为 2/3。假设所有含有序列子的蛋白质中存在相同数量的 N 连接单元和序列子占据率，并且仅 O-糖基化蛋白质的比例（约 10%）也与已充分表征的蛋白质相同，我们得出结论，大多数含有序列子的蛋白质将被发现是糖基化的，并且所有蛋白质的一半以上是糖蛋白。 (C) 1999 Elsevier Science B.V. 保留所有权利。
The SWISS-PROT protein sequence data bank contains at present nearly 75000 entries, almost two thirds of which include the potential N-glycosylation consensus sequence, or sequon, NXS/T (where X call be any amino acid but proline) and thus may be glycoproteins. The number of proteins filed as glycoproteins is however considerably smaller, 7942, of which 749 have been characterized with respect to the total number of their carbohydrate units and sites of attachment of the latter to the protein, as well as the nature of the carbohydrate-peptide linking group. Of these well characterized glycoproteins, about 90% carry either N-linked carbohydrate units alone or both N- and O-linked ones, attached at 1297 N-glycosylation sites (1.9 per glycoprotein molecule) and the rest are O-glycosylated only. Since the total number of sequons in the well characterized glycoproteins is 1968, their rate of occupancy is 2/3. Assuming that the same number of N-linked units and rate of sequon occupancy occur in all sequon containing proteins and that the proportion of solely O-glycosylated proteins (ca. 10%) will also be the same as among the well characterized ones, we conclude that the majority of sequon containing proteins will be found to be glycosylated and that more than half of all proteins are glycoproteins. (C) 1999 Elsevier Science B.V. All rights reserved.