SYNTHETIC GLYCOCONJUGATES .6. PREPARATION AND BIOCHEMICAL EVALUATION OF NOVEL CLUSTER-TYPE GLYCOPOLYMERS CONTAINING GAL BETA(1-]4)GLCNAC (N-ACETYLLACTOSAMINE) RESIDUE

A simple and facile method for the syntheses of cluster-type homopolym ers from omega-(acrylamido)alkyl glycosides of N-acetyllactosamine [be ta-D-Galp-(1-->4)-beta-n-GlcpNAc] is described. An efficient procedure for the preparation of poly[omega-(acrylamido)alkyl 1-->4)-2-acetamid o-2-deoxy-beta-D-glucopyranoside] was established on the basis of radi cal polymerization of the novel glycosides in the presence of ammonium persulfate and N,N,N',N'-tetramethylethylenediamine. These synthetic cluster glycopolymers exhibited good solubility in water and had sugar densities much higher than the glycopolymers derived from known n-pen tenyl glycosides. The association constants of Erythrina corallodendro n lectin (ECorL) with these cluster glycopolymers were evaluated by me asuring the changes in fluorescence intensity of fluorescent-labeled E CorL induced by the addition of the polymeric ligands. Addition of the cluster-type glycopolymers having different degrees of N-acetyllactos amine density to ECorL induced a significant decrease of the fluoresce nce intensity at 520 nm, and this phenomenon was used for the determin ation of binding constants between the glycopolymers and ECorL.