期刊
CELL STRESS & CHAPERONES
卷 16, 期 5, 页码 475-480出版社
SPRINGER
DOI: 10.1007/s12192-011-0259-5
关键词
Chaperone activity; Lens crystallin; Lens water-soluble protein; Tauroursodeoxycholic acid; Thermal protein aggregation; Ursodeoxycholic acid
类别
资金
- RPB
- Department of Ophthalmology
- NIH [EY013968, EY0180172]
Human lens membranes contain the highest cholesterol concentration of any known biological membranes, but it significantly decreases with age. Oxygenation of cholesterol generates numerous forms of oxysterols (bile acids). We previously showed that two forms of the bile acid components-ursodeoxycholic acid (UDCA) and tauroursodeoxycholic acid (TUDCA)-suppressed lens epithelial cell death and alleviated cataract formation in galactosemic rat lenses. We investigated whether these compounds also suppress the thermal aggregation of human lens crystallins. Total water-soluble (WS) proteins were prepared from human lenses, and recombinant human crystallins (alpha A-, alpha B-, beta B2-, and gamma C-crystallin) were generated by a prokaryotic expression system and purified by liquid chromatography. The light scattering of proteins in the presence or absence of UDCA or TUDCA was measured using a spectrofluorometer set at Ex/Em = 400/400 nm. Protein blot analysis was conducted for detection of alpha-crystallins in the human lens WS proteins. High concentrations of UDCA and TUDCA significantly suppressed thermal aggregation of total lens WS proteins, which contained a low level of alpha A-/alpha B-crystallin. Spectroscopic analysis with each recombinant human lens crystallin indicated that the bile acids did not suppress the thermal aggregation of gamma C-, beta B2-, alpha A-, or alpha B-crystallin. Combination of alpha-crystallin and bile acid (either UDCA or TUDCA) suppressed thermal aggregation of each individual crystallin as well as a non-crystallin protein, insulin. These results suggest that UDCA or TUDCA protects the chaperone activity of alpha-crystallin. It is believed that these two naturally occurring intermediate waste products in the lens enhance the chaperone activity of alpha-crystallin. This finding may lead to the development of UDCA and TUDCA as anticataract agents.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据