title: Enzymatic copolymerization to hybrid glycosaminoglycans: a novel strategy for intramolecular hybridization of polysaccharides.
abstract: Hybrid glycosaminoglycans (GAGs) having an intramolecularly hybridized structure of hyaluronan-chondroitin (3a) and hyaluronan-chondroitin 4-sulfate (3b) have been synthesized via enzymatic copolymerization catalyzed by hyaluronidase (HAase). N-Acetylhyalobiuronate (GlcAbeta(1-->3)GlcNAc)-derived oxazoline (1) was copolymerized with N-acetylchondrosine (GlcAbeta(1-->3)GalNAc)-derived oxazoline (2a) by HAase catalysis at pH 7.5 and 30 degrees C, giving rise to copolymer 3a with Mn 7.4 x 103 in a 50% yield. Also, HAase-catalyzed copolymerization of monomer 1 with N-acetylchondrosine oxazoline having a sulfate group at C4 on GalNAc (2b) was carried out to produce copolymer 3b with Mn 1.4 x 104 in a 60% yield. The copolymer compositions were controllable by varying the comonomer feed ratio. These hybrid GAGs were successfully digested by the catalysis of hyaluronan lyase, clearly exhibiting that the products are not a blend of different homopolymers but an intramolecularly hybridized GAG.
authors.affiliation: Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ochiai
authors.forename: Shun-Ichi
authors.initials: S
authors.lastname: Fujikawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Ohmae
authors.forename: Shiro
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D002236:Carbohydrate Conformation; D002621:Chemistry / Q000379:methods; D002807:Chondroitin / Q000737:chemistry; D002809:Chondroitin Sulfates / Q000737:chemistry; D004187:Disaccharides / Q000737:chemistry; D006025:Glycosaminoglycans / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008968:Molecular Conformation; D010080:Oxazoles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D013997:Time Factors
chemical_list: D004187:Disaccharides; D006025:Glycosaminoglycans; D010080:Oxazoles; D011108:Polymers; D011134:Polysaccharides; C033269:N-acetylchondrosine; D006820:Hyaluronic Acid; D002807:Chondroitin; D002809:Chondroitin Sulfates