ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Abstract Peptidase D of Escherichia coli was overproduced from a multicopy plasmid and purified to electrophoretic homogeneity. The pure enzyme was stable at 4°C or −20°C and had a pH optimum at pH 9, and a pI of 4.7; the temperature optimum was at 37°C. As the enzyme was activated by Co2+ and Zn2+, and deactivated by metal chelators, it appears to be a metallopeptidase. By activity staining of native gels, 11 dipeptides which are preferentially cleaved by peptidase D were identified. Peptidase D activity required dipeptide substrates with an unblocked amino terminus and the amino group in the α or β position. Non-protein amino acids and proline were not accepted in the C-terminal position, whereas some dipeptide amides and formyl amino acids were hydrolyzed. Km values of 2 to 5 mM indicate a relatively poor interaction of the enzyme with its substrates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.1994.tb07215.x
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