| Abstract |
An intracellular protease from cells of Pseudomonas carboxydohydrogena grown on nutrient broth was purified to better than 95% homogeneity in five steps using azocaseine as a substrate. The molecular weight of the native enzyme was determined to be 125,000. Sodium dodecyl sulfate-gel electrophoresis revealedat least two non-identical subunits of molecular weight 70,000 and 56,000. The enzyme activity was completely ingibited by phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate. The enzyme was also inhibited by Mg^2+, Zn^2+, Cd^2+, Cu^2+, and Fe^2+, but was stimulated by iodoacetamide. Maximal reaction rate of the enzyme was observed at pH8.0 and 30℃. The isoelectric point of the enzyme was found to be 7.5. The enzyme was unable to hydrolyze carbon monoxide dehydrogenase. |
