caa a22 4500 475845927 CHVBK 20180406123914.0 cr unu---uuuuu 170329e20000901xx s 000 0 eng 10.1007/PL00000627 doi (NATIONALLICENCE)springer-10.1007/PL00000627 Renkonen O. Institute of Biotechnology, University of Helsinki, P.O. Box 56 FIN-00014 (Finland), Fax +358 9 191 59563, e-mail: ossi.renkonen@helsinki.fi, FI aut Enzymatic in vitro synthesis of I-branches of mammalian polylactosamines: generation of scaffolds for multiple selectin-binding saccharide determinants [Elektronische Daten] [O. Renkonen] Abstract.: Polylactosamines are covalent monosaccharide assemblies of the animal kingdom and some bacteria, and are characterized by backbones of interlinked N-acetyllactosamine units (Galβ1-4GlcNAc, LacNAc). The mammalian LacNAc arrays are linear (blood group i-type) and branched (blood group I-type), and are linked to the core elements of glycolipids as well as O- and N-glycans of glycoproteins and keratan sulfate proteoglycans. Generation of I-branches to linear i-type polylactosamines is initiated by two kinds of β6GlcNAc transferases. One type of the enzymes transfers to GlcNAcβ1-3Galβ1-OR of growing i-chains at the peridistal (underlined) Gal; these enzymes are called dIGnT (d for ‘distally acting'). The other enzymes transfer to internal Gal units of preformed i-chains; they are called cIGnT (c for ‘centrally acting'). Purified natural and recombinant enzymes of both types have been described. The structures of I-type polylactosamines result from a collaboration of dIGnTs, cIGnTs, β4GalTs and the i-chain-elongating iGnTs. At present, the interplay of these enzymes in vivo is poorly understood. By contrast, enzyme-assisted in vitro synthesis of branched polylactosamines representing distinct LacNAc arrays that are multiply capped by a variety of decorations is possible. Some of the synthetic polylactosamines reduce the lymphocyte-endothelium adhesion in a tissue-specific mode, raising the possibility of achieving local immunosuppression in the future. Useful applications of multiply decorated I-type polylactosamines may also be found in prevention of mammalian gamete adhesion and in inhibition of bacterial and viral adhesion to host tissues. Birkhäuser Verlag Basel,, 2000 Key words. Polylactosamines nationallicence polylactosaminoglycans nationallicence poly-N-acetyllactosamines nationallicence i-antigens nationallicence I-antigens nationallicence biosynthesis nationallicence enzyme-assisted synthesis nationallicence in vitro synthesis nationallicence branched backbones nationallicence cell adhesion nationallicence selectin ligands nationallicence anti-inflammatory saccharides nationallicence endothelial saccharides nationallicence sialyl Lewis x nationallicence Lex nationallicence sialyl diLex nationallicence sialyl diLex nationallicence lymphocyte extravasation nationallicence L-selectin nationallicence allograft rejection nationallicence site-specific immunosuppression nationallicence lymph nodes nationallicence inflammation nationallicence IGnT nationallicence β6GlcNAcT nationallicence https://doi.org/10.1007/PL00000627 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00000627 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Renkonen O. Institute of Biotechnology, University of Helsinki, P.O. Box 56 FIN-00014 (Finland), Fax +358 9 191 59563, e-mail: ossi.renkonen@helsinki.fi, FI aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer