International Journal of Medical Laboratory

Backgroung and Aims: L-Asparaginase II is a cornerstone of treatment protocols for acute lymphoblastic leukemia. Only asparaginase II obtained from E. coli K12 and Erwinia chrysanthemi have been used in human as therapeutic drug. The therapeutic effects of asparaginase II from E. coli K12 and Erwinia chrysanthemi is accompanied by side effects. It is desirable to search for other asparaginase II sources with novel properties that could be therapeutic and produce an enzyme with less adverse effects.

Materials and Methods: Previously, we performed the in vitro studies, including cloning, sequencing and expression of L-asparaginase II genes (ansB) from Citrobacter freundii 1101, Erwinia chrysanthemi DSM 4610, E. coli BL21 and Klebsiella pneumoniae ATCC 10031. In this article, the obtained results were compared bioinformatically. The nucleotide and amino acid sequence alignments were carried out by ClustalW2. Protein localization and signal peptides were predicted by PSORT and SIG-Pred softwares, respectively. Percentages of hydrophobic and hydrophilic residues were calculated by Genscript software. The physicochemical parameters were computed using Expasy’s ProtParam prediction server. The secondary and 3D structures were predicted by SOPMA and the online server Phyre2, respectively. The antigenicity of the asparaginase IIs was predicted using Semi-empirical method.

Results: E. coli BL21 and Citrobacter freundii 1101 had the most similarity in physicochemical parameters and antigenicity with E. coli K12. Also, Erwinia chrysanthemi DSM 4610 had the most similarity in physicochemical parameters and antigenicity with Erwinia chrysanthemi.

Conclusions: In spite of these similarities with drug types, the potentiality of other low-similar asparaginase IIs should also be determined and compared with drug types.