| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new enzyme capable of releasing the amino acid-pro of the substrate of prolidase, useful for the high utilization of protein, relatively high in thermal stability, wide in the optimal pH range, and originated from bacteria. SOLUTION: This dipeptide peptidase IV having the below-described properties is obtained by culturing Xanthomonas maltophilia AJ-131227, FERM-P-14986. (1) The enzyme specifically acts on a peptide having Pro or Ala at the second position from the amino terminal, and is hydrolyzed at a pH of 6.0-10.5 to release a dipetide having Pro or Ala at the CO2 terminal. (2) The enzyme has the optimal pH of 6.0-10.0, and is stable at a pH range of 7.0-9.0. (3) The enzyme has the optimal temperature of 40-60 deg.C, and is stable at 35-55 deg.C. (4) The mol.wt. is 150,000-170,000 (by a gel filtration method) or 750,000-90,000 (SDS-PAGE). (5) The enzyme is inhibited with HgCl2 or diisopropylphosphofluoridate. |
