title: Purification and characterization of an extracellular adenosine deaminase from Nocardioides sp. J-326TK.
abstract: An extracellular adenosine deaminase was isolated from the culture supernatant of Nocardioides sp. J-326TK and purified 193-fold to homogeneity. It had a specific activity of 4677 units/mg at 37 degrees C, was a monomeric protein as judged by SDS/PAGE, and was characterized with respect to M(r) (80,000 and 72,000 by gel filtration on Sephadex G-200 and SDS/PAGE respectively), pH optimum (6.0), temperature optimum (50 degrees C) and pI (7.6). The adsorption spectrum of the enzyme had a maximum at 280 nm and a minimum at 250 nm. The enzyme was stable at pH 6.5-7.5 and at temperatures below 30 degrees C. Adenosine and 2'-deoxyadenosine were deaminated and the respective Km values were 0.22 and 0.20 mM, but the enzyme was not active on adenine and 6-(gamma gamma'-dimethylallylamino)purine riboside. The enzyme reaction was promoted by Fe3+ and Sn2+, but potently inhibited by Hg2+, Ag2+, o-phenanthroline and pentachlorophenol, and noticeably inhibited by 8-bromoadenosine, theobromine and theophylline.
authors.affiliation: Department of Microbiology, Pusan National University, Korea.
authors.forename: H K
authors.initials: HK
authors.lastname: Jun
authors.forename: T S
authors.initials: TS
authors.lastname: Kim
authors.forename: Y
authors.initials: Y
authors.lastname: Yeeh
mesh_terms: D000243:Adenosine Deaminase / Q000096:biosynthesis / Q000187:drug effects / Q000302:isolation & purification*; D003470:Culture Media; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000096:biosynthesis / Q000187:drug effects / Q000302:isolation & purification*; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D009618:Nocardiaceae / Q000201:enzymology*; D009705:Nucleosides / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D003470:Culture Media; D007527:Isoenzymes; D008670:Metals; D009705:Nucleosides; D000243:Adenosine Deaminase