title: Purification of a dimeric arginine deiminase from Enterococcus faecium GR7 and study of its anti-cancerous activity.
abstract: The arginine deiminase (ADI, E.C 3.5.3.6) - a key enzyme of ADI pathway of Enterococcus faecium GR7 was purified to homogeneity. A sequential purification strategy involving ammonium sulfate fractionation, molecular sieve followed by Sephadex G-100 gel filtration was applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified with a fold of 16.92 and showed a final specific activity of 76.65IU/mg with a 49.17% yield. The dimeric ADI has a molecular mass of about 94,364.929Da, and comprises of hetrodimers of 49.1kDa and 46.5kDa as determined by MALDI-TOF and PAGE analysis. To assess anti-cancerous activity of ADI by MTT assay was carried out against cancer cell lines (MCF-7, Sp2/0-Ag14 and Hep-G2). Purified ADI exhibited the most profound antiproliferative activity against Hep-G2 cells; with half-maximal inhibitory concentration (IC50) of 1.95μg/ml. Purified ADI from E. faecium GR7 was observed to induce apoptosis in the Hep-G2 cells by DNA fragmentation assay. Our findings suggest the possibility of a future use of ADI from E. faecium GR7 as a potential anticancer drug.
authors.affiliation: Department of Biotechnology, Punjabi University, Patiala 147002, Punjab, India. Electronic address: baljinderbt@gmail.com.
authors.forename: Baljinder
authors.initials: B
authors.lastname: Kaur
authors.affiliation: Department of Biotechnology, Punjabi University, Patiala 147002, Punjab, India.
authors.forename: Rajinder
authors.initials: R
authors.lastname: Kaur
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002850:Chromatography, Gel; D016984:Enterococcus faecium / Q000201:enzymology*; D004789:Enzyme Activation; D015870:Gene Expression; D056945:Hep G2 Cells; D006801:Humans; D006867:Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D008970:Molecular Weight; D055503:Protein Multimerization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000970:Antineoplastic Agents; D006867:Hydrolases; C019723:arginine deiminase
keywords: Apoptosis; Arginine deiminase; Enterococcus faecium; Lactic acid bacteria