Purification and Some Properties of Dipeptidyl Carboxypeptidase fromBacillus pumilus

Abstract

An intracellular protease from a bacterium, Bacillus pumilus HL721, was purified about 5000-fold by chromatography with a Q-Sepharose Fast Flow column, TSK-gel HA-1000 glass column, and TSK-gel G3000SWXL column using Bz-Gly-Ala-Pro as a substrate. The enzyme was the most active at pH around 7.5 and stable from 4.5 and 8.0. The enzyme activity was inhibited by Cu2+, EDTA, N-ethylmaleimide, o-phenanthroline, and p-chloromercuribenzoic acid. The molecular weight of the enzyme was 155,000 by gel filtration. The enzyme removed dipeptide from the carboxyl end of some peptides used as substrates. From these results the enzyme seems to be a dipeptidyl carboxypeptidase.

Purification and Characterization of a Dipeptidyl Carboxypeptidase from Pseudomonas sp. WO24

“…B) On the other hand, the physiological role of microbial DCP remains entirely unexplained. There have been several reports on DCPs of microbial origin, [14][15][16][17][18][19][20] and only DCPs from Escherichia coli 21) and Salmonella typhimurium 22 ) have been cloned and sequenced. This enzyme may serve as a tool in various fields, such as dietetics, the food industry,23) and analytical biochemistry.24) For example, DCP in combination with dipeptidyl aminopeptidase (DAP), has been used in procedures to analyze the primary structures of polypeptides.…”