作者:Andrew N. Savel'ev、Farid M. Ibatyllin、Elena V. Eneyskaya、Anatoly M. Kachurin、Kirill N. Neustroev
DOI:10.1016/s0008-6215(96)00248-0
日期:1996.12
compounds have been obtained. The inhibiting properties of the competitive inhibitors of d -galactose, 1,5-anhydro- d -galactitol, and 2-deoxygalactose have been compared, and reasons for differences in KI values between these compounds have been discussed. It has been shown that α- d -galactosidase exhibits transglycosylating activity; the main product of transglycosylation in the reaction with PNPG is p-nitrophenyl
摘要天然和合成底物[甲基纤维素,棉子糖,水苏糖,甲基α-d-吡喃半乳糖苷和对硝基苯基α-d-吡喃半乳糖苷(PNPG)]的水解动力学,由α-d-半乳糖苷酶催化。真菌里氏木霉,已被研究。已经合成了许多作为α-d-半乳糖苷酶的竞争性抑制剂的N-酰基-α-d-吡喃半乳糖苷胺,并且已经获得了这些化合物的KI值。比较了d-半乳糖,1,5-脱水d-半乳糖醇和2-脱氧半乳糖的竞争性抑制剂的抑制性能,并讨论了这些化合物之间KI值差异的原因。已经显示出α-d-半乳糖苷酶表现出转糖基化活性。与PNPG反应的转糖基化的主要产物是对硝基苯基6-O-α-d-吡喃半乳糖苷-α-d-吡喃半乳糖苷。已显示在底物存在下的水解抑制与底物转糖基化相关。稳态动力学的数据以及通过停流方法获得的稳态前的动力学数据表明,在反应中形成了中间半乳糖基-酶复合物,在所研究的过程中特别重要。提出了描述所获得的实验数据的最小动力学方案。稳态动力学