Journal Article

Differential ligand binding by two subunits of the rat liver asialoglycoprotein receptor

Nydia I. Ruiz and Kurt Drickamer

in Glycobiology

Published on behalf of Society for Glycobiology

Volume 6, issue 5, pages 551-559
Published in print July 1996 | ISSN: 0959-6658
e-ISSN: 1460-2423 | DOI: http://dx.doi.org/10.1093/glycob/6.5.551
Differential ligand binding by two subunits of the rat liver asialoglycoprotein receptor

Show Summary Details

Preview

The rat liver asialoglycoprotein receptor consists of two types of subunits, a predominant polypeptide designated rat hepatic lectin 1 (RHL-1) and a minor polypeptide, RHL-2/3, that comes in two differentially glycosylated forms. The exact stoichiometry and arrangement of the subunits in the RHL oligomer are not known. The carbohydrate-recognition domain of RHL-2/ has been prepared by limited proteolysis of the liver receptor so that its properties can be compared with those of the corresponding domain of RHL-1 previously produced in a bacterial expression system. Binding studies indicate that while RHL-1 binds N-acetylgalactosamine with approximately 60-fold higher affinity than it binds galactose, RHL-2/ has only 2-fold selectivity for N-acetylgalactosamine. In general, the pattern of monosaccharide-binding specificity for RHL-2/ is similar to RHL-1, but the discrimination of various sugars relative to galactose is reduced substantially. Limited proteolysis and crosslinking studies demonstrate that RHL- 2/ is easily removed from the RHL oligomer in detergent solution and that RHL-1 remains at least trimeric following removal of RHL-2/. These studies suggest that RHL-1 forms a ligand-binding core while RHL-2/ acts more as an accessory subunit contributing to selective binding of certain oligosaccharide structures.

Keywords: asialoglycoprotein receptor; binding; carbohydrate recognition; lectin; proteolysis

Journal Article.  0 words. 

Subjects: Carbohydrates

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.