title: Marine bacterial sulfated fucoglucuronomannan (SFGM) lyase digests brown algal SFGM into trisaccharides.
abstract: Three kinds of trisaccharides were prepared by digesting fucoidan from the brown alga Kjellmaniella crassifolia, with the extracellular enzymes of the marine bacterium Fucobacter marina. Their structures were determined as delta 4,5GlcpUA1-2(L-Fucp(3-O-sulfate)alpha 1-3)D-Manp, delta 4,5GlcpUA1-2(L-Fucp(3- O-sulfate)alpha 1-3)D-Manp(6-O-sulfate), and delta 4,5GlcpUA1-2(L-Fucp(2,4-O-disulfate)alpha 1-3)D-Manp(6-O-sulfate), which indicated the existence of a novel polysaccharide in the fucoidan and a novel glycosidase in the extracellular enzymes. In order to determine the complete structure of the polysaccharide and the reaction mechanism of the glycosidase, the fucoidan was partially hydrolyzed to obtain glucuronomannan, which is the putative backbone of the polysaccharide, and its sugar sequence was determined as (-4-D-GlcpUAbeta 1-2D-Manpalpha 1-)n, which disclosed that the main structure of the polysaccharide is (-4-D-GlcpUAbeta 1-2(L-Fucp(3-O-sulfate)alpha 1-3)D-Manpalpha 1-)n. Consequently, the glycosidase was deduced to be an endo-alpha-D-mannosidase that eliminatively cleaves the alpha-D-mannosyl linkage between D-Manp and D-GlcpUA residues in the polysaccharide and produces the above trisaccharides. The novel polysaccharide and glycosidase were tentatively named as sulfated fucoglucuronomannan (SFGM) and SFGM lyase, respectively.
authors.affiliation: Takara Shuzo Co., Ltd., Biomedical Group, Zaifu-cho 82-4, Hirosaki-shi, Aomori-ken, 036-8216, Japan. sakait@takara-bio.co.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sakai
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kimura
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kojima
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shimanaka
authors.forename: Katsushige
authors.initials: K
authors.lastname: Ikai
authors.forename: Ikunoshin
authors.initials: I
authors.lastname: Kato
mesh_terms: D001419:Bacteria / Q000201:enzymology; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification*; D008351:Mannans / Q000737:chemistry / Q000302:isolation & purification*; D000459:Phaeophyceae / Q000737:chemistry; D011133:Polysaccharide-Lyases / Q000737:chemistry / Q000302:isolation & purification*; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D012623:Seawater / Q000382:microbiology; D013463:Sulfuric Acid Esters / Q000737:chemistry / Q000302:isolation & purification*; D014312:Trisaccharides / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D008351:Mannans; D011134:Polysaccharides; D013463:Sulfuric Acid Esters; D014312:Trisaccharides; C007789:fucoidan; D006026:Glycoside Hydrolases; D011133:Polysaccharide-Lyases