title: Conformational studies on the N-linked carbohydrate chain of bromelain.
abstract: 1H- and 13C-NMR assignments for the carbohydrate part of the glycopeptide alpha-D-Man-(1----6)-[beta-D-Xyl-(1----2)]-beta-D-Man-(1----4)-beta-D- GlcNAc-(1----4)-[alpha-L-Fuc-(1----3)]-beta-D-GlcNAc-(1----N)-Asn approximately, derived from the proteolytic enzyme bromelain (EC 3.4.22.4), have been obtained using homo- and heteronuclear correlation spectroscopy, two-dimensional homonuclear Hartmann-Hahn and nuclear Overhauser enhancement experiments. A conformational model for the carbohydrate chain, deduced from the NMR data and consistent with hard-sphere exo-anomeric calculations shows that the rotamer population about the C-5--C-6 bond of beta-Man is restricted to the P omega = 180 rotamer, mainly.
authors.affiliation: Department of Bio-Organic Chemistry, Utrecht University, The Netherlands.
authors.forename: J B
authors.initials: JB
authors.lastname: Bouwstra
authors.forename: E C
authors.initials: EC
authors.lastname: Spoelstra
authors.forename: P
authors.initials: P
authors.lastname: De Waard
authors.forename: B R
authors.initials: BR
authors.lastname: Leeflang
authors.forename: J P
authors.initials: JP
authors.lastname: Kamerling
authors.forename: J F
authors.initials: JF
authors.lastname: Vliegenthart
mesh_terms: D001963:Bromelains / Q000032:analysis*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis*; D006020:Glycopeptides / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data
chemical_list: D002241:Carbohydrates; D006020:Glycopeptides; D001963:Bromelains