Purification of the medium-chain/long-chain (COT/CPT) carnitine acyltransferase of rat liver microsomes.
A procedure for the purification of the rat liver microsomal carnitine octanoyltransferase (COT) that catalyzes the reversible formation of medium-chain and long-chain acylcarnitines from acyl-coenzyme A is described. The K0.5 for L-carnitine is 0.6 mM and the K0.5 for both decanoyl-CoA and palmitoyl-CoA is 0.6 microM. The Vmax with decanoyl-CoA is approximately fourfold greater than the Vmax with palmitoyl-CoA. The enzyme is monomeric, sodium dodecyl sulfate-polyacrylamide gel electrophoresis gives a molecular weight of 50,100, and molecular sieving gives a molecular weight of 54,300. Purified COT does not cross-react with either antimitochondrial carnitine palmitoyltransferase or antiperoxisomal COT antibodies. It also does not form a covalent adduct when incubated with etomoxiryl-CoA. Microsomal COT is a different protein than either mitochondrial carnitine palmitoyltransferase or peroxisomal COT.
Murthy
M S
MS
Department of Biochemistry, Michigan State University, East Lansing 48824.
Bieber
L L
LL
D000214:Acyl Coenzyme A / Q000494:pharmacology; D000818:Animals; D001391:Azo Compounds; D002333:Carnitine Acyltransferases / Q000302:isolation & purification*; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D002846:Chromatography, Affinity; D002847:Chromatography, Agarose; D002850:Chromatography, Gel; D004396:Coloring Agents; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology*; D009281:Naphthalenes; D051381:Rats; D014227:Triazines
D000214:Acyl Coenzyme A; D001391:Azo Compounds; D004396:Coloring Agents; D009281:Naphthalenes; D014227:Triazines; C077864:etomoxiryl-coenzyme A; C012842:Cibacron Blue F 3GA; C048536:matrex gel orange A; D002333:Carnitine Acyltransferases; C030162:carnitine octanoyltransferase; D002334:Carnitine O-Palmitoyltransferase