Abstract
Leucine aminopeptidase (LAP) from marine labyrinthulid strain 00-Bat-05 cells were purified and characterized by enzymological properties. The optimum temperature and pH of LAP from strain 00-Bat-05 was 37°C and pH 8.0, respectively. The thermostability of the enzyme was indicated by remaining 80% of maximum activity after heat treatment at 60°C for 10 min. The enzyme were inactivated by p-chloromercuribenzoic acid (PCMB), 1,10-phenanthroline, bestatin and sodium dodecyl sulphate (SDS), suggesting that it is SH-aminopeptidase. The enzyme activity of LAP was stimulated by Co2+ and inhibited by Zn2+. LAP of 00-Bat-05 had a high specificity for L-leucine-p-nitroanilide among p-nitroanilide derivatives of L-amino acids tested.
