Decreased subunit exchange of heat-treated lens alpha A-crystallin.
Decreased subunit exchange of heat-treated lens alpha A-crystallin.
复制标题
热处理晶状体 α A-晶状体蛋白的亚基交换减少。
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
L. Fu
中科院分区：
文献类型：
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作者：
Jack Liang;L. Fu
通过在80-90 ℃下预热制备α A-晶体蛋白高分子量（HMW）聚集体，并使用光谱测量进行研究。基于增加的bis-ANS（4，4（'）-二苯胺基-1，1（'）-联萘-5，5（'）-二磺酸）和ThT（硫磺素T）荧光以及增加的远紫外和减少的近紫外圆二色性（CD）的数据，提出了构象差异。这些结果表明，HMW聚集的α-晶状体蛋白比天然α-晶状体蛋白更疏水，可能是由于α-晶状体蛋白的部分解折叠。α A-晶状体蛋白中的两个半胱氨酸在HMW聚集体中大部分被氧化。用荧光共振能量转移法研究了高分子聚集对动态结构的影响，亚基交换变慢。这些结果强烈表明，HMW α A-晶状体蛋白聚集体是由埋藏的β-折叠片层暴露和疏水相互作用增加引起的。
alpha A-Crystallin high-molecular-weight (HMW) aggregates were prepared by preheating at 80-90 degrees C and studied using spectroscopic measurements. Conformational differences were suggested based on data of increased bis-ANS (4,4(')-dianilino-1,1(')-binaphthalene-5,5(')-disulfonic acid) and ThT (thioflavin T) fluorescence as well as increased far-UV and decreased near-UV circular dichroism (CD). These results indicated that HMW aggregated alpha-crystallin was more hydrophobic than the native alpha-crystallin, possibly resulting from partial unfolding of alpha-crystallin. The two cysteines in alpha A-crystallin were mostly oxidized in HMW aggregates. The effects of HMW aggregation on the dynamic structure were studied with fluorescence resonance energy transfer; subunit exchange became slower. These results strongly suggest that HMW alpha A-crystallin aggregates result from exposure of buried beta-pleated sheets and increased hydrophobic interaction.