title: Kinetic properties of Streptomyces canarius L- Glutaminase and its anticancer efficiency.
abstract: L-glutaminase was produced by Streptomyces canarius FR (KC460654) with an apparent molecular mass of 44 kDa. It has 17.9 purification fold with a final specific activity 132.2 U/mg proteins and 28% yield recovery. The purified L-glutaminase showed a maximal activity against L-glutamine when incubated at pH 8.0 at 40 °C for 30 min. It maintained its stability at wide range of pH from 5.0 11.0 and thermal stable up to 60 °C with Tm value 57.5 °C. It has high affinity and catalytic activity for L-glutamine (Km 0.129 mM, Vmax 2.02 U/mg/min), followed by L-asparagine and L-aspartic acid. In vivo, L-glutaminase showed no observed changes in liver; kidney functions; hematological parameters and slight effect on RBCs and level of platelets after 10 days of rabbit's injection. The anticancer activity of L-glutaminase was also tested against five types of human cancer cell lines using MTT assay in vitro. L-glutaminase has a significant efficiency against Hep-G2 cell (IC50, 6.8 μg/mL) and HeLa cells (IC50, 8.3 μg/mL), while the growth of MCF-7 cells was not affected. L-glutaminase has a moderate cytotoxic effect against HCT-116 cell (IC50, 64.7 μg/mL) and RAW 264.7 cell (IC50, 59.3 μg/mL).
authors.affiliation: Department of Botany and Microbiology, Zagazig University, Zagazig, Egypt.
authors.forename: Fifi M
authors.initials: FM
authors.lastname: Reda
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D055162:Biocatalysis; D049109:Cell Proliferation / Q000187:drug effects; D004795:Enzyme Stability; D005972:Glutaminase / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D005973:Glutamine / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D007700:Kinetics; D013302:Streptomyces / Q000737:chemistry / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D000970:Antineoplastic Agents; D005973:Glutamine; D005972:Glutaminase