| Abstract |
The extracellular adenine deaminase from Nocardioides sp. J-275L was purified by the following techniques: ammonium sulfate fractionation, DEAE-Cellulose, DEAE-Sephadex A-50 column chromatography, and Sephacryl S-200 superfine gel filtration. The enzyme was partially purified about 3889.5-fold with about 5.2% yield by these procedures. The molecular weight of the enzyme was 39,000 by a calibrated Sephacryl S-200 superfine column chromatography. The enzyme was stable at pH 7.5 and up to 40℃. Glycerol was effective on the stabilization of the enzyme during storage. The optimum pH and temperature of the enzyme were around pH 7.5 and 40℃, respectively. The apparent Michaelis constant Km of the enzyme for adenine was 7.4×10^-5M. The purine analogues, 6-chloropurine, 2,6-diaminopurine, 6-bromopurine, 4-aminopyrazolo [3.4-d]pyrimidine, and 8-azaadenine were substrates for the enzyme. 6-Dimethylaminopurine was a competitive inhibitor of the enzyme. The enzyme was inhibited by 1mM of Cu^2+, Fe^3+, Pb^2+, Hg^2+, and Ag^+, and 1mM of α, α'-dipyridyl, pentachlorophenol, and pCMB. |
