PURIFICATION AND CHARACTERIZATION OF CARNITINE ACYLTRANSFERASE FROM HIGHER-PLANT MITOCHONDRIA

Carnitine acyltransferase was purified to homogeneity from mung-bean (Vigna radiata L.) hypocotyl mitochondria. The native enzyme has an apparent M(r) of 45 000 as measured by gel filtration. SDS-PAGE revealed the same indicating a monomeric structure. The enzyme is active with short- and long-chain acyl-CoAs. The activity ratio determined for the substrate acetyl-CoA and palmitoyl-CoA remained the same throughout purification. The ability of the enzyme to use acetyl-CoA and palmitoyl-CoA as substrates is unique amongst the carnitine acyltransferases characterized to date. Apparent K-m values for the enzyme substrates acetyl-CoA, palmitoyl-CoA, and L-carnitine were: 8.5, 2.5 and 5 mu M, respectively.