The major in vivo modifications of the human water-insoluble lens crystallins are disulfide bonds, deamidation, methionine oxidation and backbone cleavage
The major in vivo modifications of the human water-insoluble lens crystallins are disulfide bonds, deamidation, methionine oxidation and backbone cleavage
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DOI：
10.1006/exer.2000.0868
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发表时间：
2000-08-01
影响因子：
3.4
通讯作者：
Smith, JB
中科院分区：
文献类型：
--
作者：
Hanson, SRA;Hasan, A;Smith, JB
这项研究的水不溶性晶体蛋白从人类晶状体已使用多个色谱分离，以获得足够的纯度的蛋白质质谱分析。分析每个级分以确定组成蛋白质的分子量以及这些蛋白质的胰蛋白酶解物中的肽。水不溶性晶体蛋白的主要组分被鉴定为α A-和α B-晶体蛋白。此外，还发现了γ S-、β B1-、γ D-、β A3/A1-和β B2-晶体蛋白，其丰度依次降低。虽然有一些骨架断裂的证据，但α A-、α B、β B2-、γ S-和γ D-晶体蛋白的主要形式是完整的多肽链。区分水溶性晶体蛋白的主要修饰是二硫键的增加、Met的氧化、Gln和Asn的脱酰胺和骨架断裂。这些结果最有力地支持金属催化的氧化、脱酰胺和截短作为有利于聚集的构象变化的引发剂。(C)北京大学出版社.
This investigation of the water-insoluble crystallins from human lenses has used multiple chromatographic separations to obtain proteins of sufficient purity for mass spectrometric analysis. Each fraction was analysed to determine the molecular masses of the constituent proteins as well as peptides in tryptic digests of these proteins. The major components of the water-insoluble crystallins were identified as alpha A-and alpha B-crystallins. In addition, gamma S-, beta B1-, gamma D-, beta A3/A1- and beta B2-crystallins were found, in order of decreasing abundance. Although there was evidence of some backbone cleavage, the predominant forms of alpha A-, alpha B, beta B2-, gamma S- and gamma D-crystallins were the intact polypeptide chains, The major modifications distinguishing the water-soluble crystallins were increased disulfide bonding, oxidation of Met, deamidation of Gin and Asn and backbone cleavage, Of the many reactions hypothesized to lead to crystallin insolubility and cataract, these results most strongly support metal-catalysed oxidation, deamidation and truncation as initiators of conformational changes that Favor aggregation. (C) 2000 Academic Press.