Fridjonsson O, Watzlawick H, Gehweiler A, Mattes R
Institut für Industrielle Genetik, Universität Stuttgart, Germany.
FEMS Microbiol Lett. 1999 Jul 1;176(1):147-53. doi: 10.1111/j.1574-6968.1999.tb13655.x.
An alpha-galactosidase gene from the thermophilic bacterium Bacillus stearothermophilus NUB3621 was cloned, sequenced, expressed in Escherichia coli and the recombinant protein was purified. The Bacillus enzyme, designated AgaN, is similar to alpha-galactosidases of family 36 in the classification of glycosyl hydrolases. The enzyme was estimated to be a tetramer with a molecular mass of subunits 80.3 kDa. The purified AgaN is thermostable and has a temperature optimum of activity at 75 degrees C and a half-life of inactivation of 19 h at 70 degrees C. AgaN displays high affinity for oligomeric substrates such as melibiose and raffinose and is able to hydrolyze raffinose in the presence of 60% sucrose with high efficiency.
克隆并测序了嗜热脂肪芽孢杆菌NUB3621的α-半乳糖苷酶基因，在大肠杆菌中表达该基因并纯化了重组蛋白。该芽孢杆菌酶命名为AgaN，在糖基水解酶分类中与36家族的α-半乳糖苷酶相似。该酶估计为四聚体，亚基分子量为80.3 kDa。纯化的AgaN具有热稳定性，最适活性温度为75℃，在70℃下失活半衰期为19小时。AgaN对低聚底物如蜜二糖和棉子糖具有高亲和力，并且能够在60%蔗糖存在下高效水解棉子糖。
