晶状体蛋白的外消旋化及其在白内障发病机制中的研究进展

摘要

外消旋化是老年人晶状体蛋白中重要的翻译后修饰类型.多项研究发现,随着年龄的增长,α-、β-及γ-晶状体蛋白中的部分L型氨基酸残基倾向于通过外消旋化反应转化为D型氨基酸残基,导致晶状体蛋白的构象改变,聚合形成的大分子蛋白质在晶状体核区和皮质中逐渐积累,晶状体蛋白失去了原有功能而不能维持晶状体的透明度.外消旋化在晶状体蛋白年龄相关性改变中的效应和参与程度,及其对白内障发生与进展的具体机制都值得进一步研究.%Racemization is probably the most abundant post-translational modification (PTM) in aged lens.According to previous studies,L-amino acid in α,β and γ crystallins are tend to transfer into D-amino acid with aging,leading to a series of age-related changes in the structure,metabolism and function of lens.Aggregated highmolecular-weight proteins gradually accumulate in both nuclear and cortex region,which will have a negative effect on the function of crystallins and finally lead to capacity of lens.Moreover,it is likely that racemization of crystallins eventually leads to cataract formation and development as well.The material effect and mechanism of racemization changes in human age-related lens still requires further research.