Deamidation and disulfide bonding in human lens γ-crystallins
Deamidation and disulfide bonding in human lens γ-crystallins
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DOI：
10.1006/exer.1998.0530
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发表时间：
1998-09-01
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;Smith, DL;Smith, JB
对存在于人晶状体的水溶性部分中的三种γ-晶状体蛋白（γ S、γ D和γ C）的详细分析已经确定二硫键和脱酰胺作用为这些晶状体蛋白的主要翻译后修饰。采用色谱和质谱技术分离和鉴定了32周龄、0日龄、4日龄、19岁、31岁、45岁和55岁正常晶状体中的水溶性γ-晶体蛋白。γ-晶状体蛋白的氨基酸序列通过对分离的晶状体蛋白的酶消化或化学片段化产生的肽进行质谱分析来确认和/或校正。肽的分子量也用于鉴定、定位和定量修饰。每个γ-晶体蛋白具有两个二硫键以及几个脱酰胺的谷氨酰胺和天冬酰胺残基。随着透镜的老化，二硫键形成和脱酰胺的程度似乎增加。对正常人透镜γ-晶体蛋白的检查是γ-晶体蛋白的第一个详细表征，将为与在水不溶性部分和白内障晶状体中发现的修饰进行比较提供基础。(C)北京：科学出版社.
Detailed analysis of the three gamma-crystallins present in the water-soluble portion of human lenses, gamma S, gamma D and gamma C, has identified disulfide bonding and deamidation as the major post-translational modifications of these crystallins. Chromatographic and mass spectrometric techniques were used to isolate and identify water-soluble gamma-crystallins from normal lenses, ages 32 week gestation, 0 day old, 4 day old, 19, 31, 45 and 55 year old. The amino acid sequences of the gamma-crystallins were confirmed and/or corrected by mass spectrometric analysis of peptides produced by enzymatic digestion or chemical fragmentation of the isolated crystallins. The molecular weight of peptides were also used to identify, locate and quantify modifications. Each of the gamma-crystallins had two disulfide bonds as well as several deamidated glutamine and asparagine residues. The extent of disulfide bond formation and deamidation appeared to increase with the age of the lens. This examination of normal human lens gamma-crystallins, the first detailed characterization of the gamma-crystallins, will provide a basis fbr comparison with modifications found in the water-insoluble portion and in cataractous lenses. (C) 1998 Academic Press.