title: Endohexosaminidase-catalysed glycosylation with oxazoline donors: effects of organic co-solvent and pH on reactions catalysed by Endo A and Endo M.
abstract: The synthetic efficiency of endohexosaminidase-catalysed glycosylation reactions using N-glycan oxazolines as donors was investigated as two reaction parameters were varied. Both the addition of quantities of an organic co-solvent and modulation of reaction pH between 6.5 and 8.0 were found to have different effects on reactions catalysed by either Endo A (and two available mutants) or Endo M, indicating subtle differences between these two family GH85 enzymes. Fine tuning of reaction pH, or the addition of quantities of an organic co-solvent, resulted in beneficial increases in achievable synthetic efficiency by effecting a reduction in the rate of competitive hydrolytic processes.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
authors.forename: Christoph D
authors.initials: CD
authors.lastname: Heidecke
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Parsons
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Fairbanks
mesh_terms: D002384:Catalysis; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000378:metabolism*; D009930:Organic Chemicals / Q000138:chemical synthesis; D010080:Oxazoles / Q000737:chemistry / Q000378:metabolism*; D012997:Solvents
chemical_list: D009930:Organic Chemicals; D010080:Oxazoles; D012997:Solvents; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase