Basu P S, Biswas C, Majhi R, Datta T K
Indian Institute of Chemical Biology, Calcutta, India.
Indian J Biochem Biophys. 1996 Dec;33(6):491-7.
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+.
从四日龄的饭豆（Vigna umbellata (Thunb)）发芽种子中，通过硫酸铵沉淀、凝胶过滤、离子交换色谱和高效液相色谱（HPLC），纯化出一种分子量为16,000 Da的类胰蛋白酶丝氨酸蛋白酶，该酶在pH 8.4时对N-苯甲酰精氨酸乙酯（BAEE）具有最佳活性。通过聚丙烯酰胺凝胶电泳（PAGE）检测该酶的纯度。研究了该酶对酪蛋白、血红蛋白和饭豆贮藏蛋白豌豆球蛋白等天然底物的活性。该酶的活性被苯甲基磺酰氟完全抑制，但不受碘乙酰胺和HgCl2抑制，表明它是一种丝氨酸蛋白酶。加入Ca2+可逆转在EDTA存在下的活性丧失。
