3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase (HMGCR) ELISA Kit for Human

HMG-CoA reductase is the rate-limiting enzyme for cholesterol synthesis and is regulated via a negative feedback mechanism mediated by sterols and non-sterol metabolites derived from mevalonate, the product of the reaction catalyzed by reductase. Normally in mammalian cells this enzyme is suppressed by cholesterol derived from the internalization and degradation of low density lipoprotein (LDL) via the LDL receptor. Competitive inhibitors of the reductase induce the expression of LDL receptors in the liver, which in turn increases the catabolism of plasma LDL and lowers the plasma concentration of cholesterol, an important determinant of atherosclerosis. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2008]

Function: Transmembrane glycoprotein that is the rate-limiting enzyme in cholesterol biosynthesis as well as in the biosynthesis of nonsterol isoprenoids that are essential for normal cell function including ubiquinone and geranylgeranyl proteins.

Catalytic activity: (R)-mevalonate + CoA + 2 NADP+ = (S)-3-hydroxy-3-methylglutaryl-CoA + 2 NADPH.

Enzyme regulation: Regulated by a negative feedback mechanism through sterols and non-sterol metabolites derived from mevalonate. Inhibited by statins, a class of hypolipidemic agents used as pharmaceuticals to lower cholesterol levels in individuals at risk from cardiovascular disease due to hypercholesterolemia. Inhibition of HMGCR in the liver stimulates the LDL-receptors, which results in an increased clearance of LDL from the bloodstream and a decrease in blood cholesterol levels. The first results can be seen after one week of statin use and the effect is maximal after four to six weeks.1 PublicationManual assertion based on experiment in:Ref.7