Enzymatic properties of dipeptidyl carboxypeptidase (DCP) from Bacillus pumilus were investigated. The enzyme was more active on tri- and tetrapeptides than angiotensin-converting enzyme (ACE) from rabbit lung. The presence of chloride ion is essential for the hydrolysis. The Km value of angiotensin I for the enzyme was 0.119 x 10(-3) M. The enzyme was not inhibited by the mammalian ACE inhibitors lisinopril and enalaprilat. The enzyme is readily inhibited by EDTA but restored by Co2+, Mn2+, and Zn2+. Therefore, it seems to be a zinc-metallo protease.

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Enzymatic properties of dipeptidyl carboxypeptidase (DCP) from Bacillus pumilus were investigated. The enzyme was more active on tri- and tetrapeptides than angiotensin-converting enzyme (ACE) from rabbit lung. The presence of chloride ion is essential for the hydrolysis. The Km value of angiotensin I for the enzyme was 0.119 x 10(-3) M. The enzyme was not inhibited by the mammalian ACE inhibitors lisinopril and enalaprilat. The enzyme is readily inhibited by EDTA but restored by Co2+, Mn2+, and Zn2+. Therefore, it seems to be a zinc-metallo protease.

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.

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.