Available Online: http://www.ejpau.media.pl/volume15/issue4/abs-03.html
PROTEOLYTIC ACTIVITY OF PSEUDOMONAS CHLORORAPHIS 5N ISOLATED FROM RHIZOSPHERE SOIL
Urszula Jankiewicz1, Magdalena Fr±k2
1 Department of Biochemistry, Warsaw University of Life Sciences – SGGW, Poland
2 Department of Biochemistry, Department of Enviromental Improvement Warsaw University of Life Sciences, Poland
A Gram-negative bacterial strain characterized by high proteolytic activity was isolated from rhizosphere soil under winter wheat. Morphological and biochemical testing as well as analysis of 16S rRNA gene sequence identified the strain as Pseudomonas chlororaphis. In this study an extracellular endopeptidase synthesized by the strain was purified and characterized. The enzyme showed highest activity at pH 11 and at temperature 42°C. The molecular weight determined by SDS-PAGE was approx. 51 kDa. The studied endopeptidase was characterized by low thermal stability in the 37-45°C range. The activity of the enzyme was strongly inhibited by specific metallopeptidase inhibitors, which allowed classifying the studied protein as a metalloendopeptidase. Ca2+ and Mg2+ ions stimulated the activity of the enzyme, whereas Mn2+, Co2+ and Cu2+ ions inhibited it.
Key words: endopeptidase, metallopeptidase, purification.
Department of Biochemistry, Warsaw University of Life Sciences – SGGW, Poland
Department of Biochemistry, Department of Enviromental Improvement
Warsaw University of Life Sciences, Poland
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