Elucidation of the specific function of the conserved threonine triad responsible for human L-asparaginase autocleavage and substrate hydrolysis.

ABSTRACT: Our long-term goal is the design of a human l-asparaginase (hASNase3) variant, suitable for use in cancer therapy without the immunogenicity problems associated with the currently used bacterial enzymes. Asparaginases catalyze the hydrolysis of the amino acid asparagine to aspartate and ammonia. The key property allowing for the depletion of blood asparagine by bacterial asparaginases is their low micromolar KM value. In contrast, human enzymes have a millimolar KM for asparagine. Toward the goal of engineering an hASNase3 variant with micromolar KM, we conducted a structure/function analysis of the conserved catalytic threonine triad of this human enzyme. As a member of the N-terminal nucleophile family, to become enzymatically active, hASNase3 must undergo autocleavage between residues G

SUBMITTER: Nomme J 

PROVIDER: S-EPMC4120204 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature