PURIFICATION AND CHARACTERIZATION OF A PROTEINASE FROM THE PROBIOTIC Lactobacillus rhamnosus OXY |
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Authors: | Adam Waśko Marek Kieliszek Zdzisław Targoński |
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Affiliation: | 1. Department of Biotechnology , Human Nutrition and Science of Food Commodities, University of Life Sciences , Lublin , Poland awasko1@tlen.pl;3. Department of Food Biotechnology and Microbiology , Warsaw University of Life Sciences , Warsaw , Poland;4. Department of Technical Microbiology , Institute of Agricultural and Food Biotechnology , Warsaw , Poland;5. Department of Biotechnology , Human Nutrition and Science of Food Commodities, University of Life Sciences , Lublin , Poland |
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Abstract: | A proteinase produced by the human gastrointestinal isolate Lactobacillus rhamnosus strain OXY was identified and characterized. The prtR2 gene coding for proteinase activity was detected in the examined strain. The PCR primers used were constructed on the basis of the sequence of the prtR2 proteinase gene from Lactobacillus rhamnosus GG. The enzyme was purified by fast protein liquid chromatography (FPLC) using CM-Sepharose Fast Flow and Sephacryl S-300 columns. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the enzyme had a relatively low molecular mass of 60 kD. Protease activity was observed at a pH range from 6.5 to 7.5 with optimum k cat/K m values at pH 7.0 and 40°C. Maximum proteolytic activity (59 U mL?1) was achieved after 48 hr of cultivation. The activity of the enzyme was inhibited only by irreversible inhibitors specific for serine proteinases (PMSF and 3,4-dichloro-isocumarine), suggesting that the enzyme was a serine proteinase. Proteinase activity was increased by Ca2+ and Mg2+, and inhibited by Cu2+, Zn2+, Cd2+, and Fe2+. |
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Keywords: | Lactobacillus rhamnosus proteinase purification |
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