Turnover of membrane proteins: Kinetics of induction and degradation of seven forms of rat liver microsomal cytochrome P-450, NADPH-cytochrome P-450 reductase, and epoxide hydrolase

摘要: The in vivo turnover of several rat liver microsomal proteins was studied using techniques designed to maximize antibody recognition specificity and minimize reutilization radioactive labels. kinetics degradation seven cytochrome P-450 isozymes, NADPH-cytochrome reductase, epoxide hydrolase were determined untreated rats treated with phenobarbital or beta-naphthoflavone. In the cases where induction these enzymes occurred above chemicals, rates synthesis also estimated. general, different rather similar each other, effects beta-naphthoflavone on not very great. However, case cytochromes P-450, a general trend observed which heme moiety degraded more rapidly than apoprotein. Changes individual appear contribute altered steady-state levels are expressed do degradation, profiles enzyme concentrations predicted by kinetic constants approximate those vivo.