PROTEIN MODIFICATION BY OXIDANTS AND THE ROLE OF PROTEOLYTIC-ENZYMES
PROTEIN MODIFICATION BY OXIDANTS AND THE ROLE OF PROTEOLYTIC-ENZYMES
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DOI：
10.1042/bst0210346
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发表时间：
1993-05-01
影响因子：
3.9
通讯作者：
DAVIES, KJA
中科院分区：
文献类型：
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作者：
DAVIES, KJA
J 在细胞质中充当水溶性自由基清除剂。最后，各种过渡金属螯合蛋白（例如转铁蛋白、铁蛋白、铜蓝蛋白）和化合物（例如尿酸）可减少或防止游离铁或铜参与自由基反应（例如亚铁催化的过氧化氢还原形成羟基自由基）。尽管抗氧化酶和化合物构成了一系列令人印象深刻的防御，但很明显，自由基氧化剂对细胞内、细胞和有机体的损害仍然以显着的速度发生。换句话说，防御并不是100%有效。然而，同样清楚的是，细胞内成分，甚至长寿细胞，很少表现出氧化损伤明显积累的迹象。基于这些观察，我最初提出细胞还必须拥有酶/系统来去除（降解）和/或修复氧化损伤的产物[2-51。这种“损伤去除/修复系统”也在图 1 中进行了描述。值得注意的是，图 1 是先前提出的（和类似）方案的自然演变，其中抗氧化防御被称为“主要防御”，损伤去除/修复系统被称为“次要防御”[2, 31。在图 1 中，我提到了可以催化去除（降解）和/或修复 氧化损伤的蛋白质、脂质和 DNA。这些“修复系统”构成了本次交流的背景。这篇特别的论文将重点讨论蛋白水解酶在去除氧化修饰的蛋白质、防止蛋白质进一步氧化或聚集以及促进蛋白质中的作用。
J act as water-soluble radical scavengers in the cytoplasm. Finally, various transition metal-chelating proteins (eg transferrin, ferritin, ceruloplasmin) and compounds (eg uric acid) diminish or prevent the involvement of free iron or copper in radical reactions (such as the ferrous iron-catalysed reduction of hydrogen peroxide to form the hydroxyl radical). Although the antioxidant enzymes and compounds comprise an impressive array of defences, it is clear that intracellular, cellular and organismal damage by radicaWoxidants still occurs at a significant rate. In other words, the defenses are not 100% effective. It is also clear, however, that intracellular components, and even long-lived cells, rarely exhibit signs of the overt accumulation of oxidative damage. On the basis of these observations, I proposed originally that cells must also possess enzymes/systems to remove (degrade) and/or repair the products of oxidative damage [2-51. Such ‘Damage RemovaVRepair Systems’ are also depicted in Figure 1. It should be noted that Figure 1 is a natural evolution of previously proposed (and similar) schemes in which antioxidant defences were referred to as ‘Primary Defenses’, and damage removal/repair systems were referred to as ‘Secondary Defences’[2, 31. In Figure 1, I allude to enzymes that can catalyse the removal (degradation) and/or repair of oxidatively damaged proteins, lipids and DNA. These ‘Repair Systems’ form the background for the present communication. This particular paper will focus on the role (s) of proteolytic enzymes in removing oxidatively modified proteins, preventing further protein oxidation or aggregation, and pro-