Purification, characterization and anticancer efficiency of L-glutaminase from Aspergillus flavus.

Purification, characterization and anticancer efficiency of L-glutaminase from Aspergillus flavus. J Gen Appl Microbiol. 2019 May 24;: Authors: Abu-Tahon MA, Isaac GS Abstract The aim of this study was to purify L-glutaminase from Aspergillus flavus. The enzyme was purified 12.47-fold from a cell-free extract with a final specific activity of 613.3 U/mg and the yield was 51.11%. The molecular weight of the enzyme, as determined by SDS-PAGE, was found to be 69 kDa. The maximal activity of L-glutaminase was recorded at pH 8 and 40°C. The highest activity was reported towards its natural substrate, L-glutamine, with an apparent Km value of 4.5 mmol and Vmax was 20 Uml-1. The enzyme was activated by Na+ and Co+2, while it was strongly inhibited by iodoacetate, NEM, Zn+2 and Hg+2 at 10 mM. L-glutaminase activity increased gradually with an increase of NaCl concentration up to 15%. In vivo, the median lethal dose (LD50) was approximately 39.4 mg/kg body weight after intraperitoneal injection in Sprague Dawley rats. Also, L-glutaminase showed no observed changes in liver and kidney functions and hematological parameters on rates. Purified A. flavus L-glutaminase had neither an appreciable effect on human platelet aggregation nor hemolytic activity. In addition, MTT assay showed that the purified L-glutaminase has a high toxic effect on Hela and Hep G2 cell lines with an IC50 value 18 and 12 μg/ml, respectively, and a moderate cytotoxic ef...
Source: Journal of General and Applied Microbiology - Category: Microbiology Tags: J Gen Appl Microbiol Source Type: research