The fluorescence of scorpions and cataractogenesis
The fluorescence of scorpions and cataractogenesis
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DOI：
10.1016/s1074-5521(99)80085-4
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发表时间：
1999-08-01
影响因子：
--
通讯作者：
Van Vranken, DL
中科院分区：
文献类型：
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作者：
Stachel, SJ;Stockwell, SA;Van Vranken, DL
背景：蛋白质交联和荧光是公认的人类蛋白质氧化老化的标志物。氧化蛋白质老化是一个组合过程，其中多样性源于靶标的异质性，并因反应物的非选择性性质而放大。交联本身无法进行分析，因为它们通常嵌入共价基质中。节肢动物依靠氧化交联来硬化角质层，这一过程称为硬化。在节肢动物中，蝎子值得注意，因为硬化过程伴随着强烈的可见荧光的积累。迄今为止，荧光物种的性质仍然是个谜。 结果：我们已经鉴定出 Centuroides vittatus 和 Pandinus imperator 蝎子的一种可溶性荧光成分是 β-咔啉 - 一种色氨酸衍生物，之前通过晶状体蛋白的水解和氧化来鉴定。我们还表明，β-咔啉-3-羧酸在水解时从蝎子蜕皮（脱落的角质层）和人类白内障中释放出来，这表明蛋白质结合的β-咔啉和游离的β-咔啉具有共同的化学起源。结论：白内障发生和角质层硬化是不同的氧化过程 - 前者是并行的，后者是组成性的。 β-咔啉的常见形成表明相似的反应模式是有效的。这些基本机制为人类蛋白质老化的后果提供了预测性见解。
Background: Protein cross-linking and fluorescence are widely recognized markers of oxidative aging in human proteins. Oxidative protein aging is a combinatorial process in which diversity arises from the heterogeneity of the targets and is amplified by the nonselective nature of the reactants. The crosslinks themselves defy analysis because they are generally embedded in a covalent matrix. Arthropods rely upon oxidative cross-linking in the hardening of the cuticle - a process known as sclerotization, Among arthropods, scorpions are noteworthy in that the process of sclerotization is accompanied by the buildup of strong visible fluorescence. To date, the nature of the fluorescent species has remained a mystery.Results: We have identified one of the soluble fluorescent components of the scorpions Centuroides vittatus and Pandinus imperator as beta-carboline -a tryptophan derivative that has previously been identified by hydrolysis and oxidation of lens protein. We have also shown that beta-carboline-3-carboxylic acid is released from both scorpion exuvia (the shed cuticle) and human cataracts upon hydrolysis, suggesting that the protein-bound beta-carboline and free beta-carboline have common chemical origins.Conclusions: Cataractogenesis and cuticular sclerotization are disparate oxidative processes - the former is collateral and the latter is constitutive. The common formation of beta-carbolines shows that similar patterns of reactivity are operative. These fundamental mechanisms provide predictive insight into the consequences of human protein aging.