title: Enzymatic synthesis of complex glycosaminotrioses and study of their molecular recognition by hevein domains.
abstract: Hevein, a protein found in Hevea brasiliensis, has a CRD domain, which is known to bind chitin and GlcNAc-containing oligosaccharides. By using NMR and molecular modeling as major tools we have demonstrated that trisaccharides containing GalNAc and ManNAc residues are also recognized by hevein domains. Thus far unknown trisaccharides GlcNAcbeta(1-->4)GlcNAcbeta(1-->4)ManNAc (1) and GalNAcbeta(1-->4)GlcNAcbeta(1-->4)ManNAc (2) were synthesized with the use of beta-N-acetylhexosaminidase from Aspergillus oryzae. This method is based on the rather unique phenomenon that some fungal beta-N-acetylhexosaminidases cannot hydrolyze disaccharide GlcNAcbeta(1-->4)ManNAc (5) contrary to chitobiose GlcNAcbeta(1-->4)GlcNAc (4) that is cleaved and, therefore, cannot be used as an acceptor for further transglycosylation. Both trisaccharides 1 and 2 were prepared by transglycosylation from disaccharidic acceptor in good yields ranging from 35% to 40%. Our observations strongly indicate that the present nature of the modifications of chitotriose (GlcNAcbeta(1-->lcNAcbeta(1-->4)GlcNAc, 3) at either the non-reducing end (GalNAc instead of GlcNAc) or at the reducing end (ManNAc instead of GlcNAc) do not modify the mode of binding of the trisaccharide to hevein. The association constant values indicate that chitotriose (3) binding is better than that of 1 and 2, and that the binding of (with ManNAc at the reducing end) is favored with respect to that of 2 (with ManNAc at the reducing end with a non-reducing GalNAc moiety).
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, Madrid, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Aboitiz
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Cañada
authors.forename: Lucie
authors.initials: L
authors.lastname: Husakova
authors.forename: Marek
authors.initials: M
authors.lastname: Kuzma
authors.forename: Vladimír
authors.initials: V
authors.lastname: Kren
authors.forename: Jesús
authors.initials: J
authors.lastname: Jiménez-Barbero
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry; D023181:Antimicrobial Cationic Peptides; D001236:Aspergillus oryzae / Q000201:enzymology; D002240:Carbohydrate Sequence; D002686:Chitin / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D037121:Plant Lectins / Q000737:chemistry*; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D014312:Trisaccharides / Q000138:chemical synthesis; D001619:beta-N-Acetylhexosaminidases / Q000737:chemistry*
chemical_list: D023181:Antimicrobial Cationic Peptides; D009844:Oligosaccharides; D037121:Plant Lectins; D014312:Trisaccharides; C045875:hevein; D002686:Chitin; D001619:beta-N-Acetylhexosaminidases; D000117:Acetylglucosamine