A new mechanism of regulation of rat liver acetyl-CoA carboxylase activity.
A factor has been found in rat liver supernatant solution which inhibits acetyl-CoA carboxylase activity regardless of the presence or absence of Mg2+ and ATP. Inactivation of the enzyme has been demonstrated via radiochemical and spectrophotometric assay procedures. The inactivation of acetyl-CoA carboxylase is not attributable to either malonyl-CoA decarboxylase activity, to phosphorylation of the enzyme, or to action on substrates or cofactors of the reaction. The activity of the inhibitor is destroyed by heating to 70-80 degrees C for 5 min or by treatment with trypsin. Dialyzing the inhibitor for 24 h at 4 degrees C does not alter its activity in inhibiting acetyl-CoA carboxylase. Hence, it appears that the inhibitor is a regulatory protein that acts directly on acetyl-CoA carboxylase.
D000103:Acetyl-CoA Carboxylase / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D003600:Cytosol / Q000201:enzymology; D007700:Kinetics; D008025:Ligases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D011506:Proteins / Q000502:physiology*; D051381:Rats; D014357:Trypsin / Q000494:pharmacology
D011506:Proteins; D014357:Trypsin; D008025:Ligases; D000103:Acetyl-CoA Carboxylase; D008274:Magnesium