title: The acceptor and site specificity of alpha 3-fucosyltransferase V. High reactivity of the proximal and low of the distal galbeta 1-4GlcNAc unit in i-type polylactosamines.
abstract: We report here on in vitro acceptor and site specificity of recombinant alpha3-fucosyltransferase V (Fuc-TV) with 40 oligosaccharide acceptors. Galbeta1-4GlcNAc (LN) and GalNAcbeta1-4GlcNAc (LDN) reacted rapidly; Galbeta1-3GlcNAc (LNB) reacted moderately, and GlcNAcbeta1-4GlcNAc (N, N'-diacetyl-chitobiose) reacted slowly yet distinctly. In neutral and terminally alpha3-sialylated polylactosamines of i-type, the reducing end LN unit reacted rapidly and the distal (sialyl)LN group very slowly; the midchain LNs revealed intermediate reactivities. The data suggest that a distal LN neighbor enhances but a proximal LN neighbor reduces the reactivity of the midchain LNs. This implies that Fuc-TV may bind preferably the tetrasaccharide sequence Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAc for transfer at the underlined monosaccharide. Terminal alpha3-sialylation of i-type polylactosamines almost doubled the reactivities of the LN units at all positions of the chains. We conclude that, in comparison with human Fuc-TIV and Fuc-TIX, Fuc-TV reacted with a highly distinct site specificity with i-type polylactosamines. The Fuc-TV reactivity of free LNB resembled that of LNBbeta1-3'R of a polylactosamine, contrasting strongly with the dissimilarity of the reactivities of the analogous pair of LN and LNbeta1-3'R. This observation supports the notion that LN and LNB may be functionally bound at distinct sites on Fuc-TV surface. Our data show that Fuc-TV worked well with a very wide range of LN-glycans, showing weak reactivity only with distal (sialyl)LN units of i-type polylactosamines, biantennary N-glycans, and I branches of polylactosamines.
authors.affiliation: Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Pykäri
authors.forename: S
authors.initials: S
authors.lastname: Toivonen
authors.forename: J
authors.initials: J
authors.lastname: Natunen
authors.forename: R
authors.initials: R
authors.lastname: Niemela
authors.forename: H
authors.initials: H
authors.lastname: Salminen
authors.forename: O
authors.initials: O
authors.lastname: Aitio
authors.forename: M
authors.initials: M
authors.lastname: Ekström
authors.forename: P
authors.initials: P
authors.lastname: Parmanne
authors.forename: M
authors.initials: M
authors.lastname: Välimäki
authors.forename: J
authors.initials: J
authors.lastname: Alais
authors.forename: C
authors.initials: C
authors.lastname: Augé
authors.forename: J B
authors.initials: JB
authors.lastname: Lowe
authors.forename: O
authors.initials: O
authors.lastname: Renkonen
authors.forename: R
authors.initials: R
authors.lastname: Renkonen
mesh_terms: D000116:Acetylgalactosamine / Q000378:metabolism*; D000606:Amino Sugars / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D002240:Carbohydrate Sequence; D006224:Cricetinae; D005647:Fucosyltransferases / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D000606:Amino Sugars; D011134:Polysaccharides; C066929:polylactosamine; D005647:Fucosyltransferases; C418611:alpha3-fucosyltransferase V; D000116:Acetylgalactosamine