PARTIAL-PURIFICATION AND INITIAL STUDIES OF PREPHENATE AMINOTRANSFERASE FROM AN AMYCOLATOPSIS-METHANOLICA MUTANT

Amycolatopsis methanolica mutant GH141 is an auxotrophic strain able t o grow on glucose mineral media without supplements at reduced doublin g time (4 h); L-phenylalanine alone, and L-phenylalanine plus L-tyrosi ne mixtures, stimulated the doubling time to 3 and 2 h, respectively. Prephenate aminotransferase was isolated and partially purified from t his strain; the molecular weight of the enzyme was estimated to be 83 kD by gel filtration. The prephenate AT showed its maximum activity at 60 degrees C and at a pH range of 7.5-8.0. The enzyme was specific fo r L-glutamate as amino donor, and prephenate as amino acceptor; the ki netic constants (K-m) for prephenate and for L-glutamate were 0.37 and 13.76 mM, respectively.