Enzymatic in vitro synthesis of radiolabeled pentasaccharides GlcNAcβ1-3(Galβ1-4GlcNAcβl-6)Galβ1-4GlcNAc/Glc and the isomeric Galβ1-4GlcNAcβ1-3(GlcNAcβ1-6)Galβ1-4GlcNAc/Glc

Four radiolabeled pentasaccharides, GlcNAcβ1-3(Galβ1-4GlcNAcβ1-6)Galβ1-4GlcNAc, Galβ1-4GlcNAcβ1-3-(GlcNAcβ1-6)Galβ1-4GlcNAc, GlcNAcβ1-3(Galβ1-4GlcNAcβ1-6)Galβ1-4Glc, and Galβ1-4GlcNAcβ1-3(GlcNAcβ1-6)-Galβ1-4Glc, were prepared in virtually pure form. They were obtained by partial enzymic β1,4-galactosylations of the appropriate tetrasaccharide acceptors or by partial enzymic degalactosylations of the appropriate hexasaccharides, followed by paper chromatographic separations. All four pentasaccharides contain two nonidentical distal branches, making them valuable primers for enzymatic in vitro synthesis of larger oligo(N-acetyllactosaminoglycans).Key words: In vitro synthesis, branched pentasaccharides, backbones of oligo(N-acetyllactosaminoglycans).