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Biochemical characterization of an alkaline metallopeptidase secreted by a Pseudomonas fluorescens isolated from soil
Author(s) -
Jankiewicz Urszula,
Szawłowska Urszula,
Sobańska Monika
Publication year - 2010
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.200900054
Subject(s) - pseudomonas fluorescens , endopeptidase , enzyme , biochemistry , bacteria , chemistry , pseudomonas , egta , pseudomonadaceae , molecular mass , enzyme assay , biology , calcium , genetics , organic chemistry
The extracellular endopeptidase synthesized by soil bacterium Pseudomonas fluorescens was purified to homogeneity in a four‐step procedure. The enzyme was purified 45‐fold, with a 20% recovery. The endopeptidase appeared to be a monomer with a molecular mass of approx. 50 kDa. The enzyme was active in the pH range of 7 to 10. The optimal activity was detected at pH 9.0 and at 42 °C. Enzyme activity was inhibited by EDTA, EGTA and 1,10 phenanthroline, typical metalloprotease inhibitors. Ca 2+ activated the enzyme while Zn 2+ , Co 2+ , Cd 2+ (in high concentration) strongly inhibited it. The presence of calcium ions strongly stabilized the enzyme with regard to thermal resistance. The amino acid sequence of fragments of the enzymatic protein determined by MS analysis revealed a high similarity to the sequences of other alkaline metalloendopeptidases of bacteria belonging to the genus Pseudomonas. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)