食品与发酵工业2012，Vol.38Issue(5)：65-69,5.
根霉胞内α-半乳糖苷酶的分离及其酶学性质
Purification and Characterization of Intracellular α-galactosidase from Rhizopus sp. AOI
王剑锋 1陈今朝 2李江 1饶军1
作者信息
- 1. 东华理工大学生物系,江西抚州344000
- 2. 长江师范学院生命科学与技术学院,重庆408100
- 折叠
摘要
Abstract
Using three-phase partitioning followed by filtration chromatography with Sephadex G - 100, an intra- cellular α-galactosidase from Rhizopus sp. A01 grown on soya bean dregs broth was purified to homogeneity with a 54. 8 - fold increase in specific activity and 27.3% recovery. The relative molecular weight of the enzyme was about 302 ku through gel filtration and 85.6 ku through SDS-polyacrylamide gel electrophoresis, suggesting that the native enzyme was a tetramer. The α-galactosidase showed high activity against p-nitrophenyl-α-d-galactopyranoside （pNP-Gal） but had little activity for melibiose and raffinose, and the optimal activity was observed at pH 4.5 and 55℃. The kinetic parameters of Km and kcat/Km were 0. 242 ＋ 0. 027 mmol/L and 4. 089 × 105 L/（mol· s） with pNPGal, and the rates of hydrolysis for melibiose and raffinose were 138.3 μmol/（h · mg） and 19.7 μmol/（h · mg）, respec-tively. The enzyme activity was significantly activated by Fe2^2＋ and Fe^3＋ , but strongly inhibited by Mn^2＋ ,Cu^2＋ ,Hg^＋ and Mg^2＋ at 5.0 mmol/L. The α-galactosidase was highly stable over pH range from 4.0 to 8.2 at 25 ℃ , and it re-tained approximately 48% of the original activity after incubation for 90min at 50℃.关键词
棉子糖/蜜二糖/α-半乳糖苷酶/三相分离Key words
raffinose/melibiose/α-galactosidase/three-phase partitioning分类
化学化工引用本文复制引用
王剑锋,陈今朝,李江,饶军..根霉胞内α-半乳糖苷酶的分离及其酶学性质[J].食品与发酵工业,2012,38(5):65-69,5.
