Effect of pH on malonyl-CoA inhibition of carnitine palmitoyltransferase I.
Malonyl-CoA inhibition of carnitine palmitoyltransferase I was found to be very pH-dependent. Malonyl-CoA concentrations causing 50% inhibition (I50) at pH 6.0, 6.5, 7.0, 7.5 and 8.0 were 0.04, 1, 9, 40 and 200 microM respectively. It is suggested that a lowering of intracellular pH, such as might occur in ketoacidosis, may attenuate hepatic fatty acid oxidation by increasing malonyl-CoA sensitivity of carnitine palmitoyltransferase I.
D000214:Acyl Coenzyme A / Q000494:pharmacology*; D000217:Acyltransferases / Q000037:antagonists & inhibitors*; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors*; D005260:Female; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008316:Malonyl Coenzyme A / Q000494:pharmacology*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
D000214:Acyl Coenzyme A; D007527:Isoenzymes; D008316:Malonyl Coenzyme A; D000217:Acyltransferases; D002334:Carnitine O-Palmitoyltransferase