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：1979
卷号：76
期号：8
页码：3834-3838
DOI：10.1073/pnas.76.8.3834
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The immunotitration of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase [mevalonate:NADP+ oxidoreductase [CoA-acylating), EC 1.1.1.34 ], the major regulatory enzyme in cholesterol biosynthesis, by HMG-CoA reductase antiserum is described. This technique provides the advantage that one can rapidly measure relative changes in both enzyme concentration and enzyme activity in different physiological states by using enzyme samples all the way from crude liver microsomes to purified enzyme. Regarding the diurnal rhythm of HMG-CoA reductase, the major difference noted between animals killed near the middle of the dark period (D 4.5) compared to animals killed near the middle of the light period (L 4.5) was in the concentrations of HMG-CoA reductase present, rather than in the activity of the enzyme, with substantially more enzyme found near mid-dark. Cholestyramine treatment resulted in both an increased concentration of HMG-CoA reductase and a catalytically more active enzyme. On the other hand, cholesterol feeding resulted in both a decreased concentration of HMG-CoA reductase and a catalytically less active enzyme.
