Introduction: The bacterial enzyme has gained more attention in therapeutic application because of the higher substrate specificity and longer half-life. L-asparaginase is an important enzyme with known antineoplastic effect against acute lymphoblastic leukemia (ALL). Methods: Novel L-asparaginase genes were identified from a locally isolated halo-thermotolerant Bacillus strain and the recombinant enzymes were overexpressed in modified E. coli strains, Origami TM B and BL21. In addition, the biochemical properties of the purified enzymes were characterized, and the enzyme activity was evaluated at different temperatures, pH, and substrate concentrations. Results: The concentration of pure soluble enzyme obtained from Origami strain was ~30 mg/L of bacterial culture, which indicates the significant improvement compared to L-asparaginase produced by E. coli BL21 strain. The catalytic activity assay on the identified L-asparaginases (ansA1 and ansA3 genes) from Bacillus sp. SL-1 demonstrated that only ansA1 gene codes an active and stable homologue (ASPase A1) with high substrate affinity toward L-asparagine. The K cat and K m values for the purified ASPase A1 enzyme were 23.96 s-1 and 10.66 µM, respectively. In addition, the recombinant ASPase A1 enzyme from Bacillus sp. SL-1 possessed higher specificity to L-asparagine than L-glutamine. The ASPase A1 enzyme was highly thermostable and resistant to the wide range of pH 4.5–10. Conclusion: The biochemical properties of the novel ASPase A1 derived from Bacillus sp. SL-l indicated a great potential for the identified enzyme in pharmaceutical and industrial applications.
CITATION STYLE
Safary, A., Moniri, R., Hamzeh-Mivehroud, M., & Dastmalchi, S. (2019). Highly efficient novel recombinant L-asparaginase with no glutaminase activity from a new halo-thermotolerant Bacillus strain. BioImpacts, 9(1), 15–23. https://doi.org/10.15171/bi.2019.03
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