MATURE CARNITINE PALMITOYLTRANSFERASE-I RETAINS THE N-TERMINUS OF THENASCENT PROTEIN IN RAT-LIVER

Carnitine palmitoyltransferase I was isolated from octylglucoside extr acts of rat liver mitochondrial outer membranes. This native enzyme wa s digested proteolytically with V8 protease. Five major peptides were obtained all of which were found in the amino acid sequence predicted from the full-length cDNA sequence of the protein. One peptide was fou nd to correspond to the extreme N-terminus of the deduced amino acid s equence. Therefore, the mature protein retains the N-terminus of the n ascent protein after import into the mitochondrial membrane. Knowledge of the identity of the N-terminus of the mature protein allows a reap praisal of the role of the two main, N-terminal hydrophobic domains of the protein and of the possible topology of the protein within the me mbrane.