Abstract
Chlamydomonas sp. strain W80 is characteristically different from known Chlamydomonas types because of having tolerance to salt and cadmium. In this study, cystein protease from the cells of C. sp strain W80 (W80CP) was purified and characterized. W80CP was purified by five steps of chromatography using hydrophobic, ion-exchange and gel-filtration. This procedure resulted in a purification of 3090-fold with a yield of 2.6%. Its activity was optimal at pH 8.0. The Km value for Boc-LRR-MCA was estimated to be 0.44 μM. W80CP was not inhibited by PMSF and EDTA and also not activated by cations, but fairly inhibited by cystein protease inhibitors, leupeptin and N-ethylmaleimide, suggesting that this enzyme is cystein protease. Molecular weight of W80CP was determined to be approximately 102 k. Analysis of SDS-PAGE of W80CP suggests that W80CP is dimer. We are now studying amino acid sequence of this enzyme and cloning of the gene.
