NEW PROLINE DIPEPTIDASE AND ITS PRODUCTION

摘要

PURPOSE:To obtain a new thermostable proline dipeptidase used as research reagents, enzymes for bioreactors, etc. CONSTITUTION:A thermostable proline dipeptidase, derived from Thermus'quaticus YT-1 strain (ATCC251O4) and having about 320000 molecular weight (measured by a gel filtration method). Optimum pH; 7.0-7.5. Optimum temperature; 70-80 deg.C. Residual activity; >=70% after 48hr by using Leu-Pro as a substrate and a 50mM phosphate buffer solution (pH 7.5) at 0.5mug/ml concentration and 60 deg.C. Strongly inhibited by treatment with EDTA and 2- mercaptoethanol. Activated with Co<2+>, Mor Zn<2+> after treatment with the EDTA. An octamer enzyme of subunits capable of exhibiting about 40000 molecular weight by SDS electrophoresis. The aforementioned enzyme is obtained by ultrasonically crushing and extracting microbial cells of the Thermu.aquaticus YT-1 strain (ATCC25104) and purifying the resultant extract using suitable combination of salting out with ammonium sulfate and operation such as EDTA-Sephacel(R) and phenyl-Sepharose(R), etc.