FLUORESCENCE-LABELED SYNTHETIC GLYCOPOLYMERS - A NEW-TYPE OF SUGAR LIGANDS OF LECTINS

Radical copolymerization of a polymerizable dansyl derivative, N-2-pro penyl-(5-dimethylamino)-1-naphthalene sulfonamide, with sugar monomers and acrylamide proceeded smoothly in aqueous solution in the presence of ammonium persulfate and N,N,N',N'-tetramethylethylenediamine and a fforded a novel type of water-soluble glycopolymers having fluorescent side-chains, Fluorescence emission spectra of these polymeric sugar-l igands by excitation at 340 nm revealed maxims at 448 and 528 nm, When the glycopolymer carrying galactose residues was saturated with Ricin us communis agglutinin (RCA(60)), the fluorescence emission maxima at 448 and 528 nm were not shifted significantly, although the fluorescen ce intensities were decreased by 20 and 14%, respectively. Polymeric s ugar-cluster effects drastically enhanced the association constants of galactose residues with RCA(60) in the order of 10(8) M(-1). The sign ificance for efficient binding of galactose density on the glycopolyme r was also demonstrated by using glycopolymers with different degrees of galactose branching.