Download MendeleyDesign and Characterization of Erwinia Chrysanthemi l-Asparaginase Variants with Diminished l-Glutaminase Activity.
Nguyen, H.A., Su, Y., Lavie, A.(2016) J Biol Chem 291: 17664-17676
- PubMed: 27354283
- DOI: https://doi.org/10.1074/jbc.M116.728485
- Primary Citation of Related Structures:
5I3Z, 5I48, 5I4B - PubMed Abstract:
Current FDA-approved l-asparaginases also possess significant l-glutaminase activity, which correlates with many of the toxic side effects of these drugs. Therefore, l-asparaginases with reduced l-glutaminase activity are predicted to be safer. We exploited our recently described structures of the Erwinia chrysanthemi l-asparaginase (ErA) to inform the design of mutants with diminished ability to hydrolyze l-glutamine. Structural analysis of these variants provides insight into the molecular basis for the increased l-asparagine specificity. A primary role is attributed to the E63Q mutation that acts to hinder the correct positioning of l-glutamine but not l-asparagine. The substitution of Ser-254 with either an asparagine or a glutamine increases the l-asparagine specificity but only when combined with the E63Q mutation. The A31I mutation reduces the substrate Km value; this is a key property to allow the required therapeutic l-asparagine depletion. Significantly, an ultra-low l-glutaminase ErA variant maintained its cell killing ability. By diminishing the l-glutaminase activity of these highly active l-asparaginases, our engineered ErA variants hold promise as l-asparaginases with fewer side effects.
Organizational Affiliation:
From the Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612 and the Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois 60607.
