CARBOXY-TERMINAL CVLS-SEQUENCE-SPECIFIC PROTEIN FARNESYLTRANSFERASE FROM THE EYES OF THE SHRIMP PENAEUS-JAPONICUS - PURIFICATION AND CHARACTERIZATION

Protein farnesyltransferase from the eyes of Penaeus japonicus farnesy lates predominantly H-ras-specific carboxyl termini, with the sequence CVLS, but-not; the K-ras-specific sequence CVIM or the protein gerany lgeranyltransferase-specific sequence CAIL. The purified protein farne syltransferase from shrimp was found by immunoblotting and polyacrylam ide gel electrophoresis under denaturing conditions to consist of subu nits of Mr 49,000 and Mr 48,000. Since the active protein farnesyltran sferase was found to have a relative mass of 100,000, the purified enz yme was deduced to be a heterodimer. The enzyme had an optimal pH of 6 and a K-m of 14 +/- 1 mu M with the synthetic peptide RTRCVLSH as the substrate. The enzyme was activated by Mn++ and Mg++ but inhibited by Ca++ ions. (C) 1996 wiley-Liss, Inc.