SERRAPEPTIDASE GENE OF SERRATIA MARCESCENS FROM PLANT ORIGIN EXPRESSED BY PICHIA PASTORIS HAS PROTEASE ACTIVITY

Serrapeptidase (Spep) produced from Serratia marcescens is a secretary protein devoid of signal peptide. Spep was over expressed in E.Coli as inclusion bodies however the purified fusion protein was enzymatically inactive. To achieve the production of active Spep, in this study, the gene corresponding to Spep (Accession No. KP869847) from the genomic DNA of Serratia marcescens MTCC 8707 was cloned into Pichia pastoris using a modified transfer vector. The expression was induced with methanol and the secreted protein was affinity purified. The yield of the recombinant protein was 0.06 mg/ml with a maximum activity of 30 U/ml. An optimum activity of recombinant Spep was observed at 30oC and pH 8.0. The molecular weight of the purified mature active recombinant protein was 52 kDa. The secreted protein was characterized by mass spectrometric analyses using LC/MS-MS. To the best of our knowledge this is the first report on the production of active form of Spep from S.marcescens of plant origin. This protein may be exploited for the pharmaceutical and insecticidal application