Abstract
The yet uncharacterized ywad gene from Bacillus subtilis has been cloned and overexpressed in Escherichia coli. The gene product (BSAP) was purified and shown to be an aminopeptidase. The activity of BSAP was optimal at pH 8.4, the enzyme was stable for 20 min at 80°C and its activity was not affected by serine protease and aspartic protease inhibitors, but was completely diminished by the Zn-chelator 1,10-phenanthroline. ZnCl2 was able to restore activity, and the binding stochiometry of zinc to apo-BSAP indicated two Zn ions per protein molecule. BSAP exhibited high preference toward p-nitroanilide derived Arg, Lys, and Leu synthetic substrates resulting in k cat/Km values of 1-5 × 101 s-1 mM-1.
Original language | English |
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Pages (from-to) | 157-163 |
Number of pages | 7 |
Journal | FEMS Microbiology Letters |
Volume | 243 |
Issue number | 1 |
DOIs | |
State | Published - 1 Feb 2005 |
Bibliographical note
Funding Information:This study was supported by the Otto Meyerhof Center for Biotechnology, established by the Minerva Foundation (Munich, Germany) and the Israel Science Foundation (ISF). V.R. was supported by a Marie Curie Fellowship of the European Commission and by a Lady Davis Fellowship from the Hebrew University of Jerusalem, Israel.
Keywords
- Bacillus subtilis aminopeptidase
- Catalytic mechanism
- Substrate specificity
- Zn-metalloenzyme
- ywad gene