Biochemical characterization of L-asparaginase isoforms from Rhizobium etli-the boosting effect of zinc.

ABSTRACT: L-Asparaginases, divided into three structural Classes, catalyze the hydrolysis of L-asparagine to L-aspartic acid and ammonia. The members of Class 3, ReAIV and ReAV, encoded in the genome of the nitrogen fixing Rhizobium etli, have the same fold, active site, and quaternary structure, despite low sequence identity. In the present work we examined the biochemical consequences of this difference. ReAIV is almost twice as efficient as ReAV in asparagine hydrolysis at 37°C, with the kinetic K_M, k_cat parameters (measured in optimal buffering agent) of 1.5 mM, 770 s^-1 and 2.1 mM, 603 s^-1, respectively. The activity of ReAIV has a temperature optimum at 45°C-55°C, whereas the activity of ReAV, after reaching its optimum at 37°C, decreases drama

SUBMITTER: Sliwiak J 

PROVIDER: S-EPMC10917881 | biostudies-literature | 2024

REPOSITORIES: biostudies-literature