The properties and large-scale production of L-asparaginase from citrobacter.
An intracellular L-asparaginase with antitumour activity was purified from a strain of Citrobacter. The optimum conditions for enzyme production by fermentation on scales up to 2700 l were investigated. Highest enzyme yield was obtained in corn-steep liquor medium (9-2%, W/V) at 37 degrees C. Oxygen limitation was not necessary for high enzyme yield. A total recovery of 4-3% from nucleic-acid-free extract and a 180-fold increase in specific activity were obtained after purificaiton. The specific activity of the purified preparation was 45 i.u./mg protein. The enzyme hydrolysed D-asparagine and L-glutamine at 7 and 5%, respectively, of its activity toward L-asparagine, but L-glutaminase activity could be demonstrated only at substrate concentrations above 5 mM. The Km values for L-asparagine and D-asparagine were 2-6 X 10(-5) and 1-4 X 10(-4) respectively. The anti-lymphoma activity of the enzyme was demonstrated with Gardner lymphosarcoma and was found only slightly less potent that Crasnitin, the most active asparaginase so far tested in this system.
D000818:Animals; D001215:Asparaginase / Q000096:biosynthesis* / Q000302:isolation & purification / Q000627:therapeutic use; D001216:Asparagine / Q000378:metabolism; D002954:Citrobacter / Q000201:enzymology*; D003470:Culture Media; D004353:Drug Evaluation, Preclinical; D004755:Enterobacteriaceae / Q000201:enzymology*; D005285:Fermentation; D005972:Glutaminase / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy; D051379:Mice; D008970:Molecular Weight; D009374:Neoplasms, Experimental; D010100:Oxygen; D013237:Stereoisomerism; D013696:Temperature; D003313:Zea mays
D003470:Culture Media; D005973:Glutamine; D001216:Asparagine; D001215:Asparaginase; D005972:Glutaminase; D010100:Oxygen