[Recombinant intracellular Rhodospirillum rubrum L-asparaginase with low L-glutaminase activity and antiproliferative effect].

Abstract

The recombinant producer of Rhodospirillum rubrum L-asparaginase (RrA) was received and purification procedure of RrA was developed. It was shown that RrA has following biochemical and catalytic characteristics: K(m) for L-asn 0.22 MM, pH optimum 9.2; temperature optimum 54 degrees C; pI = 5.1 +/- 0.3; L-gln activity seems to be low-to-negligible. K562, DU145 and MDA-MB-231 cellular lines displayed significant sensitivity towards the enzyme (IC50 = 1.80; 9.19 and 34.62 ME/ml, respectively. In comparison with L-asparaginases from E. coli II type (EcA) and Erwinia carotovora (EwA) cytotoxicity of RrA seems to be higher than EwA, but lower than EcA. 10-fold i.p. RrA administration (4000 ME/kg per day) in L5178y bearing mice showed T/C = 172%. The received results show that RrA belongs to I type cellular L-asparaginases with low L-gln activity and the high antiproliferative effect.