Profiling of lens protease involved in generation of αA-66-80 crystallin peptide using an internally quenched protease substrate.
Profiling of lens protease involved in generation of αA-66-80 crystallin peptide using an internally quenched protease substrate.
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DOI：
10.1016/j.exer.2013.01.016
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发表时间：
2013-04
影响因子：
3.4
通讯作者：
Krishna Sharma K
中科院分区：
文献类型：
--
作者：
Hariharapura R;Santhoshkumar P;Krishna Sharma K
晶状体纤维细胞的蛋白质由于很少的蛋白质周转，容易积累大量的翻译后修饰。晶状体蛋白通过晶状体蛋白水解系统降解为多肽，多肽随后被下游氨基肽酶水解。低效的降解会导致蛋白质片段的积累和随后的聚集。前人研究发现αA-66-80肽及其截短产物在衰老和白内障晶状体中积累。这些肽与结晶蛋白相互作用，引起结晶蛋白聚集和沉淀。N端和c端阻断肽具有产生αA-66-80片段的裂解位点，用于检测晶状体提取物中序列特异性蛋白酶。设计、合成了一种含有晶状体蛋白酶产生αA-66-80肽序列特异性位点的内淬灭荧光肽底物，并用于表征能够在牛和人晶状体中产生αA-66-80肽的蛋白酶。我们发现在牛和人的晶状体中存在有可能产生αA-66-80肽的蛋白酶。我们还发现αA-66-80多肽可以抵抗晶状体中氨基肽酶的水解，并且可以抑制其他多肽的降解。这些肽在体内不能完全水解可导致其在晶状体中积累，随后晶状体蛋白聚集，最终可能导致白内障的形成。
Proteins of lens fiber cells are prone to accumulate extensive post-translational modifications because of very little protein turnover. Lens proteins are degraded via the lens proteolytic systems into peptides, which are subsequently hydrolyzed by downstream aminopeptidases. Inefficient degradation can lead to accumulation of protein fragments and subsequent aggregation. Previously we showed that αA-66-80 peptide and its truncated products accumulate in aging and cataract human lenses. These peptides interact with crystallins, causing crystallin aggregation and precipitation. N- and C-terminal-blocked peptides that have the cleavage sites to generate the αA-66-80 fragment were used to test lens extracts for sequence-specific proteases in lens extracts. An internally quenched fluorogenic peptide substrate containing the sequence-specific site for a lens protease to generate αA-66-80 peptide was designed, synthesized and used to characterize protease(s) that are capable of generating this peptide in bovine and human lenses. We show that proteases with the potential to generate αA-66-80 peptide are present in bovine and human lenses. We also show that the αA-66-80 peptides are resistant to hydrolysis by aminopeptidases present in the lenses and they can suppress the degradation of other peptides. Failure of complete hydrolysis of these peptides in vivo can lead to their accumulation in the lens and subsequent lens protein aggregation, which may ultimately lead to the formation of cataract.
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影响因子：
4.4
作者：
Grey AC;Schey KL
通讯作者：
Schey KL
DOI：
10.1016/s1357-2725(02)00397-7
发表时间：
2003-05-01
影响因子：
4
作者：
Hosler, MR;Wang-Su, ST;Wagner, BJ
通讯作者：
Wagner, BJ
影响因子：
2
作者：
LAFFERTY, MA;RADUCHA, M;HARRIS, H
通讯作者：
HARRIS, H
影响因子：
2
作者：
Mathur, P;Gupta, SK;Vajpayee, RB
通讯作者：
Vajpayee, RB
影响因子：
32.4
作者：
Reits, E;Neijssen, J;Neefjes, J
通讯作者：
Neefjes, J