title: Purification and characterization of a novel peroxidase from bitter gourd (Momordica charantia).
abstract: Peroxidase from bitter gourd was purified by three step purification scheme; ammonium sulphate fractionation, gel filtration and affinity chromatography. The enzyme was purified 42 fold with the retention of 67% of the initial activity. The enzyme exhibited its maximum activity at pH 5.6 and 40 degrees C. The enzyme retained half of its activity even after 1 h incubation at 60 degrees C. Molecular weight of the purified glycosylated bitter gourd peroxidase determined by Sephacryl S-100 and SDS-PAGE was 43 kDa. The stokes radius, diffusion coefficient and sedimentation coefficient of the purified peroxidase were 27.3 A, 8.17 x 10(-7) cm(2)/sec and 3.74 S, respectively. K(m) for o-dianisidine and ABTS were 1.3 and 4.9 mM, respectively. The activity of the enzyme was inhibited by sulfide, azide and L-cysteine. The carbohydrate content and sulfydryl groups of the enzyme were 25% (w/w) mass of the protein and 16 mmoles/mole of the protein, respectively.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh-202002, India.
authors.forename: Aiman
authors.initials: A
authors.lastname: Fatima
authors.forename: Qayyum
authors.initials: Q
authors.lastname: Husain
mesh_terms: D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D029777:Momordica charantia / Q000201:enzymology*; D009195:Peroxidase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D010940:Plant Proteins; D009195:Peroxidase