TOPOLOGICAL AND FUNCTIONAL-ANALYSIS OF THE RAT-LIVER CARNITINE PALMITOYLTRANSFERASE-1 EXPRESSED IN SACCHAROMYCES-CEREVISIAE

The rat liver carnitine palmitoyltransferase 1 (L-CPT 1) expressed in Saccharomyces cerevisiae was correctly inserted into the outer mitocho ndrial membrane and shared the same folded conformation as the native enzyme found in rat liver mitochondria. Comparison of the biochemical properties of the yeast-expressed L-CPT 1 with those of the native pro tein revealed the same detergent lability and similar sensitivity to m alonyl-CoA inhibition and affinity for carnitine. Normal Michaelis-Men ten kinetics towards palmitoyl-CoA were observed when careful experime ntal conditions were used for the CPT assay. Thus, the expression in S . cerevisiae is a valid model to study the structure-function relation ships of L-CPT 1. (C) 1998 Federation of European Biochemical Societie s.