title: Purification and properties of L-asparaginase B from Acinetobacter calcoaceticus.
abstract: L-Asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) B from Acinetobacter calcoaceticus has been purified by precipitation with streptomycin, chromatography on DEAE-cellulose and CM-cellulose, gel filtration on Agarose and chromatography on phosphocellulose. The molecular weight of the enzyme was found to be 130 000. The enzyme was rather insensitive to pH changes between 7 and 9. The Michaelis constant was 3-10(-3) M. Hg2+, Cu2+, and Ni2+ as well as high ionic strength inhibited the activity of the enzyme, whereas citrate seemed to stimulate the activity. The enzyme catalyzed the deamination of L-glutamine to about the same extent as L-asparagine. The temperature stability of the enzyme is also reported. The enzyme had a weak tumor inhibitory power.
mesh_terms: D000150:Acinetobacter / Q000201:enzymology*; D000818:Animals; D000970:Antineoplastic Agents; D001215:Asparaginase / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D002951:Citrates / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D005973:Glutamine / Q000378:metabolism; D007700:Kinetics; D008628:Mercury / Q000494:pharmacology; D051379:Mice; D008809:Mice, Inbred C3H; D008970:Molecular Weight; D009532:Nickel / Q000494:pharmacology; D009994:Osmolar Concentration; D013696:Temperature
chemical_list: D000970:Antineoplastic Agents; D002951:Citrates; D005973:Glutamine; D003300:Copper; D009532:Nickel; D001215:Asparaginase; D008628:Mercury