Synthesis of 4-methylumbelliferyl α-d-mannopyranosyl-(1→6)-β-d-mannopyranoside and development of a coupled fluorescent assay for GH125 exo-α-1,6-mannosidases
作者:Lehua Deng、Polina Tsybina、Katie J. Gregg、Renee Mosi、Wesley F. Zandberg、Alisdair B. Boraston、David J. Vocadlo
DOI:10.1016/j.bmc.2013.05.062
日期:2013.8
show poor activity toward aryl α-mannopyranosides. To circumvent this problem, we describe a convenient synthesis of the fluorogenic disaccharide substrate 4-methylumbelliferone α-d-mannopyranosyl-(1→6)-β-d-mannopyranoside. We show this substrate can be used in a coupled fluorescent assay by using β-mannosidases from either Cellulomonas fimi or Helix pomatia as the coupling enzyme. We find that this
某些细菌病原体拥有加工宿主N-连接聚糖的碳水化合物加工酶库,而这些酶中的许多酶对于充分危害人类病原体(例如产气荚膜梭状芽胞杆菌和肺炎链球菌)是必需的。已研究的一种细菌性碳水化合物加工酶是来自肺炎链球菌的肺炎球菌毒力因子SpGH125及其来自产气荚膜梭菌的同系物CpGH125 。来自糖苷水解酶家族125的这些exo -α-1,6-甘露糖苷酶显示出对芳基α-甘露糖吡喃糖苷的不良活性。为了解决这个问题,我们描述了一种方便的方法合成荧光二糖底物4-甲基伞形酮α- d-甘露吡喃糖基-(1→6)-β- d-甘露吡喃糖苷。我们显示该底物可通过使用来自纤维单胞菌或螺旋果树的β-甘露糖苷酶作为偶联酶用于偶联荧光测定。我们发现,CpGH125可以比芳基α-甘露糖吡喃糖苷更有效地处理该二糖底物,这很可能是因为第二甘露糖残基的加入使该底物更像该酶的天然宿主聚糖底物,使其能够更好地结合。使用这种灵敏的耦合测定,这些