首页 | 本学科首页   官方微博 | 高级检索  
检索        


Membrane lipid alpha-crystallin interaction and membrane Ca2+ -ATPase activities
Authors:Zhang Z  Zeng J  Yin H  Tang D  Borchman D  Paterson C A
Institution:Department of Ophthalmology & Visual Sciences, Kentucky Lion Eye Research Institute, University of Louisville School of Medicine, Kentucky 40292, USA.
Abstract:PURPOSE: To determine the effect of alpha-crystallin binding on lens membrane lipid characteristics and the stability of Ca2+ -ATPase activity when challenged with H2O2 or elevated temperatures. METHODS: Alpha-Crystallin binding to muscle sarcoplasmic reticulum membranes was quantified using a centrifugation protocol. Alpha-Crystallin binding to lens epithelial lipids was measured by a fluorescence energy transfer technique. Lipid phase transition temperature and lipid order was measured using fluorescence spectroscopy. Ca2+ -ATPase activity was measured using classical biochemical assays. RESULTS: The main phase transition temperatures of multilamellar vesicles composed of sphingomyelin or lipids extracted from bovine lens were 40 degrees C and 20 degrees C, respectively. In the presence of saturating amounts of alpha-crystallin, the phase transition temperature and lipid order of both sphingomyelin and lens lipid membranes remained almost the same as that without alpha-crystallin. The interaction of alpha-crystallin and lipid is likely to be restricted to the membrane surface. The binding of alpha-crystallin did not influence the oxidative or thermal inactivation of the Ca2+ -ATPase pump. CONCLUSION: Alpha-Crystallin-lens membrane binding does not protect the Ca2+ -ATPase pump from thermal derangement or oxidation by H2O2.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号