Sökning: id:"swepub:oai:DiVA.org:kth-21831" >
Mutated barley (1,3...
Mutated barley (1,3)-beta-D-glucan endohydrolases synthesize crystalline (1,3)-beta-D-glucans
- Artikel/kapitelEngelska2002
Förlag, utgivningsår, omfång ...
Nummerbeteckningar
-
LIBRIS-ID:oai:DiVA.org:kth-21831
-
https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-21831URI
-
https://doi.org/10.1074/jbc.M203971200DOI
Kompletterande språkuppgifter
-
Språk:engelska
-
Sammanfattning på:engelska
Ingår i deldatabas
Klassifikation
-
Ämneskategori:ref swepub-contenttype
-
Ämneskategori:art swepub-publicationtype
Anmärkningar
-
QC 20100525
-
Barley (1,3)-beta-D-glucan endohydrolases (EC 3.2.1.39), inactivated by site-directed mutagenesis of their catalytic nucleophiles, show autocondensation glucosynthetic activity with alpha-laminaribiosyl fluoride and heterocondensation glycosynthetic activity with a-laminaribiosyl fluoride and 4'-nitrophenyl beta-D-glucopyranoside. The native enzyme is a retaining endohydrolase of the family 17 group and catalyzes glycosyl transfer reactions at high substrate concentrations. Catalytic efficiencies (k(cat) K-m(-1)) of mutants E231G, E231S, and E231A as glycosynthases are 28.9, 0.9, and 0.5 x 10(-4) M-1 s(-1), respectively. Glycosynthase reactions appear to be processive and proceed with pH optima of 6-8 and yields of up to 75%. Insoluble products formed during the glycosynthase reaction appear as lamellar, hexagonal crystals when observed by electron microscopy. Methylation, NMR, and matrix-assisted laser desorption ionization time-of-flight analyses show that the reaction products are linear (1,3)-beta-D-glucans with a degree of polymerization of 30-34, whereas electron and x-ray diffraction patterns indicate that these (1,3)-beta-D-glucan chains adopt a parallel, triple helical conformation. The (1,3)-beta-D-glucan triple helices are orientated perpendicularly to the plane of the lamellar crystals. The barley (1,3)-beta-D-glucan glycosynthases have considerable potential for tailored and high efficiency synthesis of (1,3)-beta-D-linked oligo- and polysaccharides, some of which could have immunomodulating activity, or for the coupling of (1,3)-beta-D-linked glucosyl residues onto other oligosaccharides or glycoproteins.
Ämnesord och genrebeteckningar
-
catalytic amino-acids
-
packing analysis
-
cdna clone
-
in-vitro
-
substrate
-
polysaccharides
-
purification
-
(1->3)-beta-d-glucans
-
(1->3)-beta-glucan
-
glucosidase
Biuppslag (personer, institutioner, konferenser, titlar ...)
-
Imai, T.
(författare)
-
Rutten, S. J.
(författare)
-
Fairweather, J. K.
(författare)
-
Pelosi, L.
(författare)
-
Bulone, VincentKTH,Bioteknologi(Swepub:kth)u13o1auq
(författare)
-
Driguez, H.
(författare)
-
Fincher, G. B.
(författare)
-
KTHBioteknologi
(creator_code:org_t)
Sammanhörande titlar
-
Ingår i:Journal of Biological Chemistry277:33, s. 30102-301110021-92581083-351X
Internetlänk
Hitta via bibliotek
Till lärosätets databas