Purification, Characterization and anticancer activity of L-methionine [gamma]-lyase from thermo-tolerant Aspergillus fumigatus

Purification of L-methionine [gamma]-lyase (MGL) from A. fumigatus was sequentially conducted using heat treatment and gel filtration, resulting in 3.04 of purification fold and 73.9% of enzymatic recovery. The molecular mass of the purified MGL was approximately apparent at 46 KDa based on SDS-PAGE analysis. The enzymatic biochemical properties showed a maximum activity at pH 7 and exhibited plausible stability within pH range 5.0-7.5; meanwhile the highest catalytic activity of MGL was observed at 30-40 [degrees]C and the enzymatic stability was noted up to 40 [degrees]C. The enzyme molecule was significantly inhibited in the presence of Cu.sup.2+, Cd.sup.2+, Li.sup.2+, Mn.sup.2+, Hg.sup.2+, sodium azide, iodoacetate, and mercaptoethanol. Moreover, MGL displayed a maximum activity toward the following substrates, L-methionine < DL-methionine < Ethionine < Cysteine. Kinetic studies of MGL for L-methioninase showed catalytic activity at 20.608 mM and 12.34568 [micro]M.min.sup.-1. Furthermore, MGL exhibited anticancer activity against cancerous cell lines, where IC.sub.50 were 243 [+ or -] 4.87 [micro]g/ml (0.486 U/ml), and 726 [+ or -] 29.31 [micro]g/ml (1.452 U/ml) against Hep-G2, and HCT116 respectively. In conclusion, A. fumigatus MGL had good catalytic properties along with significantly anticancer activity at low concentration which makes it a probably candidate to apply in the enzymotherapy field.