A proportion of rat liver mitochondrial carnitine palmitoyltransferase can be made activatable by malonyl-CoA.
Treatment of rat liver mitochondrial membranes with cholate yields a soluble extract containing carnitine palmitoyltransferase (CPT) activity that is insensitive to malonyl-CoA. As found previously (I. Ghadiminejad and D. Saggerson (1990) FEBS Lett. 269, 406-408), addition of polyethylenen glycol 6000 (PEG 6000) to this extract conferred sensitivity to malonyl-CoA on the CPT. It is now shown that a sub-population of the CPT activity which is sedimentable at 7000 x g after addition of PEG 6000 is activated by malonyl-CoA, whereas the remainder is inhibited by malonyl-CoA. The presence of KCl increases the proportion of the activatable form of CPT. Possible physiological significance of this finding is discussed.
Ghadiminejad
I
I
Department of Biochemistry and Molecular Biology, University College London, U.K.
Saggerson
D
D
D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019826:Cholic Acid; D002793:Cholic Acids / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D007425:Intracellular Membranes / Q000187:drug effects; D008316:Malonyl Coenzyme A / Q000494:pharmacology*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats
D002793:Cholic Acids; D008316:Malonyl Coenzyme A; D011189:Potassium Chloride; D002334:Carnitine O-Palmitoyltransferase; D019826:Cholic Acid