title: Improved methods for the solubilization and assay of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase.
abstract: A method for solubilizing HMG-CoA reductase is described that reproducibly yielded approximately 190% of the activity assayed in rat liver microsomes. Optimal solubilization occurred when microsomal membranes were frozen at a fixed concentration, thawed, homogenized in a buffer containing 50% glycerol, and incubated at 37 degrees C for 60 minutes. A rapid spectrophotometric assay of the reductase has been developed and the optimal conditions defined. Using this assay, the kinetics were determined for HMG-CoA reductase purified to a specific activity of 17,400 nmol NADPH oxidized per minute per mg protein.
mesh_terms: D000818:Animals; D005615:Freezing; D005990:Glycerol; D006903:Hydroxymethylglutaryl CoA Reductases / Q000032:analysis* / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D006903:Hydroxymethylglutaryl CoA Reductases; D005990:Glycerol