BINDING OF D-GALACTOSE-TERMINATED LIGANDS TO RABBIT ASIALOGLYCOPROTEIN RECEPTOR

The binding affinities of a series of D-galactose-terminated glycerol glycosides and oligosaccharides for the asialoglycoprotein receptor is olated from rabbit liver were determined in vitro using a radiorecepto r-inhibition assay with I-125-asialoorosomucoid. The relative affiniti es of the synthetic ligands increased with the number of exposed D-gal actose termini. Of the compounds examined, 1,2,3-tri-O-beta-lactosylgl ycerol associated with the greatest affinity (estimated K-d = 7.97 x 1 0(-5) M). Examination of the affinities of the synthetic series indica ted that both the number and propinquity of the D-galactose termini in fluenced the strength of the binding interactions.