title: Enzymatic synthesis of 4-methylumbelliferyl (1-->3)-beta-D-glucooligosaccharides-new substrates for beta-1,3-1,4-D-glucanase.
abstract: The transglycosylation reactions catalyzed by beta-1,3-D-glucanases (laminaranases) were used to synthesize a number of 4-methylumbelliferyl (MeUmb) (1-->3)-beta-D-gluco-oligosaccharides having the common structure [beta-D-Glcp-(1-->3)](n)-beta-D-Glcp-MeUmb, where n=1-5. The beta-1,3-D-glucanases used were purified from the culture liquid of Oerskovia sp. and from a homogenate of the marine mollusc Spisula sachalinensis. Laminaran and curdlan were used as (1-->3)-beta-D-glucan donor substrates, while MeUmb-beta-D-glucoside (MeUmbGlcp) was employed as a transglycosylation acceptor. Modification of [beta-D-Glcp-(1-->3)](2)-beta-D-Glcp-MeUmb (MeUmbG(3)) gives 4,6-O-benzylidene-D-glucopyranosyl or 4,6-O-ethylidene-D-glucopyranosyl groups at the non-reducing end of artificial oligosaccharides. The structures of all oligosaccharides obtained were solved by 1H and 13C NMR spectroscopy and electrospray tandem mass spectrometry. The synthetic oligosaccharides were shown to be substrates for a beta-1,3-1,4-D-glucanase from Rhodothermus marinus, which releases MeUmb from beta-di- and beta-triglucosides and from acetal-protected beta-triglucosides. When acting upon substrates with d.p.>3, the enzyme exhibits an endolytic activity, primarily cleaving off MeUmbGlcp and MeUmbG(2).
authors.affiliation: AG Bakteriengenetik, Institut fur Biologie, Humboldt Universität Berlin Chausseestrasse 117, D-10115 Berlin, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Borriss
authors.forename: Martin
authors.initials: M
authors.lastname: Krah
authors.forename: Harry
authors.initials: H
authors.lastname: Brumer
authors.forename: Maxim A
authors.initials: MA
authors.lastname: Kerzhner
authors.forename: Dina R
authors.initials: DR
authors.lastname: Ivanen
authors.forename: Elena V
authors.initials: EV
authors.lastname: Eneyskaya
authors.forename: Lyudmila A
authors.initials: LA
authors.lastname: Elyakova
authors.forename: Sergei M
authors.initials: SM
authors.lastname: Shishlyannikov
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Shabalin
authors.forename: Kirill N
authors.initials: KN
authors.lastname: Neustroev
mesh_terms: D000818:Animals; D001419:Bacteria / Q000201:enzymology; D002240:Carbohydrate Sequence; D043326:Glucan 1,3-beta-Glucosidase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000302:isolation & purification / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008974:Mollusca / Q000201:enzymology; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D009844:Oligosaccharides; D006026:Glycoside Hydrolases; D004693:Glucan Endo-1,3-beta-D-Glucosidase; D043326:Glucan 1,3-beta-Glucosidase; C028020:licheninase