title: L-asparaginase activity in cell-free extracts of Thermoactinomyces vulgaris 13 M.E.S.
abstract: Crude extracts of Thermoactinomyces vulgaris 13 M.E.S. were prepared by different procedures and their L-asparaginase activity was compared. The optimum conditions for the enzyme activity in the crude extract was exerted at pH 8.8, using borate or tris-HCl buffer, or at pH 7.4, using phosphate buffer, after a reaction time of 30 minutes at 50-55 degrees C, using 1.35-5.4 mg protein of the crude extract. The enzyme showed an apparent km value of 4.5 x 10(-3), was more thermostable in crude extracts than in whole cells, and was inhibited by HgCl2, KCN, DL-asparagine, L-aspartic acid, and ammonium hydroxide. Enzyme purification by alcohol precipitation and gel filtration was attempted.
mesh_terms: D001215:Asparaginase / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D008848:Micromonosporaceae / Q000201:enzymology*; D013010:Sonication; D013696:Temperature
chemical_list: D001215:Asparaginase