| 摘要 |
PURPOSE:To provide the title novel isoenzyme for e.g. medicines, produced by Bacillus cells, capable of hydrolyzing D-gamma-glutamyl-p-nitroanilide, thus having such activity as to convert gamma-glutamyl groups into amino acids such as D- glutamic acid. CONSTITUTION:Bacteria belonging to Bacillus (e.g. Bacillus licheniformis A35) is inoculated into a 1% glucose-meat extract medium and put to shaking culture at 30 deg.C for 22hr followed by centrifugation of the resultant culture solution to remove microbial cells followed by addition of acetone at -30 deg.C and collection the precipitate produced, which is, in turn, suspended in a buffer solution containing 20mM potassium phosphate (pH7.0). The suspension is then subjected to anion exchange column chromatography to effect purification, thus hydrolyzing D-gamma-glutamyl-p-nitroanilide and giving the objective gamma-glutamyltranspeptidase isoenzyme having the following characteristics: (1) activity: capable of converting the gamma-glutamyl groups in the D-gamma-glutamyl-p-nitroanilide into amino acids including D-glutamic acid or peptides; (2) optimal pH: 8.0; (3) optimal temperature for activity: 55-60 deg.C; (4) molecular weight (gel filtration technique):30000. |
