Use of insect alpha-galactosyltransferase for producing alpha-galactosylated compounds, useful e.g. as antibacterial or antiviral agents, probiotics and growth promoters

摘要

Use of enzymes (I) with alpha -galactosyltransferase (aGT) activity derived from insect cells, for the enzymatic production of alpha -galactosylated compounds (II) by the transfer of galactose (Gal) on to a terminal Gal residue of a selected substrate, is new. Independent claims are also included for the following: (a) the cell line CNCM I-2045, from Mamestra brassicae; (b) cell extract with aGT, particularly alpha -1,4-aGT, activity, produced from insect cells; (c) enzymatic production of (II) by reacting UDP (uridine-diphosphate)-Gal with a substratet in presence of (I), optionally followed by purification; (d) compounds of formula (IIa); (e) pharmaceutical composition containing (IIa) and a vehicle, optionally also one or more antibiotics; and (f) food composition containing (IIa). Gal alpha 1-nGal beta 1-no-X-R (IIa) n0 = 1-4 or 6 and is the position on residue X of the carbon atom carrying a hydroxy group that binds to Gal beta 1, particularly 3 or 4; n = position of carbon atom on second Gal that carries the hydroxy group which binds to transfered Gal alpha 1; X = oside, particularly the residue of Gal, glucose (Glc), N-acetyl-D-galactosamine (GalNAc) or 2-O-acetyl-D-galactopyranose; R = hydrogen, mono- or oligo-saccharide, oside or oligoside carrying an aglycone at its reducing end, an aglycone (e.g. benzyl, phenyl (optionally substituted, particularly 4-nitrophenyl) or 1-10C alkyl, particularly 1-7C linear alkyl), glycoprotein (preferably substituted by O-glycans such as asialo-fetuin), amino acid, peptide, protein or neoglycoprotein (preferably bovine serum albumin coupled to an oligoside), glycolipid (particularly lactosylceramide or gangliosides GD3 or GM3), a lipid, a ceramide, or a multivalent non-immunogenic carrier (preferably derived from polyacrylamide or polylysine in which sidechains are substituted by Gal beta 1-n0-X).