期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1998
卷号：95
期号：3
页码：1004-1009
DOI：10.1073/pnas.95.3.1004
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We report direct experimental evidence that human B-crystallin, a member of the small heat shock protein family, actively participates in the refolding of citrate synthase (CS) in vitro. In the presence of 3.5 mM ATP, CS reactivation by B-crystallin was enhanced approximately twofold. Similarly, 3.5 mM ATP enhanced the chaperone activity of B-crystallin on the unfolding and aggregation of CS at 45{degrees}C. Consistent with these findings, cell viability at 50{degrees}C was improved nearly five orders of magnitude in Escherichia coli expressing B-crystallin. SDS/PAGE analysis of cell lysates suggested that B-crystallin protects cells against physiological stress in vivo by maintaining cytosolic proteins in their native and functional conformations. This report confirms the action of B-crystallin as a molecular chaperone both in vitro and in vivo and describes the enhancement of B-crystallin chaperone functions by ATP.
