title: Serine proteinase from rice bean.
abstract: A trypsin like serine-proteinase of M(r) 16,000 Da, optimally active at pH 8.4 on N-benzoyl-arginine ethyl ester (BAEE) was purified from 4-day old germinated seeds of rice bean, Vigna umbellata (Thunb), by ammonium sulphate precipitation, gel filtration, ion-exchange chromatography and by high performance liquid chromatography (HPLC). The purity of the enzyme was checked by polyacrylamide gel electrophoresis (PAGE). The enzyme activity was studied on natural substrates like casein, haemoglobin and vicilin, a rice bean storage protein. The activity of the enzyme was completely inhibited by phenylmethylsulfonyl fluoride, but not by iodoacetamide and HgCl2, suggesting it to be a serine protease. Loss of activity in presence of EDTA was reversed by addition of Ca2+.
authors.affiliation: Indian Institute of Chemical Biology, Calcutta, India.
authors.forename: P S
authors.initials: PS
authors.lastname: Basu
authors.forename: C
authors.initials: C
authors.lastname: Biswas
authors.forename: R
authors.initials: R
authors.lastname: Majhi
authors.forename: T K
authors.initials: TK
authors.lastname: Datta
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007887:Fabaceae / Q000201:enzymology*; D007700:Kinetics; D010946:Plants, Medicinal; D012697:Serine Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D004492:Edetic Acid; D012697:Serine Endopeptidases; D002118:Calcium