[Isolation and properties of a homogeneous L-asparaginase preparation from Pseudomonas fluorescens AG].
Highly purified L-asparaginase having a specific activity of 500+/- +/-40 IU./mg protein is isolated from Pseudomonas fluorescens AG cells. The purification procedure includes isopropanol fractionation, gel filtration through Sephadex G-100, chromatography on hydroxylapatite and DEAE-cellulose columns. The asparaginase preparation is homogenous on the basis of polyacrylamide gel electrophoresis data. The pH optimum is found to be 8.0-9.0, isoelectric point and molecular weight are 4.5+/-0.05 and 70,000+/-5,000 respectively, Km for L-asparagine being-4.1-10(-4)M. The enzyme does not hydrolyse L-glutamine. The hydrolysis rate of D-glutamine is less than 1% of the deamydation rate of L-isomer. p-Chloro-mercurium benzoate at a concentration of 10(-4) M completely inhibits the asparaginase activity. Asparaginase from Ps. fluorescens AG possesses and antileucosic activity, inhibiting 3H-thymidine incorporation into DNA of Berkit lymphoma cells.
D001215:Asparaginase / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D002051:Burkitt Lymphoma / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000096:biosynthesis; D005973:Glutamine / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008970:Molecular Weight; D011551:Pseudomonas fluorescens / Q000201:enzymology*
D002729:Chloromercuribenzoates; D004273:DNA, Neoplasm; D005973:Glutamine; D001215:Asparaginase
Vydelenie i svoistva gomogennogo preparata L-asparaginazy iz Pseudomonas fluorescens AG