Self-Association of Bovine Lung Heparan Sulphates. Identification and Characterization of Contact Zones

Publisher Website
Google Scholar
Abstract
Self-association between various heparan sulfate species and oligosaccharide fragments thereof were studied by affinity chromatography. Polysaccharides or oligosaccharides were coupled to agarose and free chains were applied at low concentrations (.ltoreq. 2 mg/ml) in 0.15 M NaCl to minimize self-association between free chains. The interaction may be specific. Heparan sulfate chains chiefly bind to gels substituted with cognate chains, i.e., the same kind or closely similar ones. Oligosaccharides of the general structure glucosamine-(iduronate/glucuronate-glucosamine)n-O-C(= CH2)-CHO were prepared by periodate oxidation/alkaline elimination and also coupled to agarose via the -CHO group. Cognate heparan sulfate chains were bound to this affinity matrix with the same affinity as in the case of heparan-sulfate-agarose. Free oligosaccharides were not bound to oligosaccharide-agarose, nor to the corresponding heparan-sulfate-agarose. Oligosaccharides of the same size and containing only iduronate were ineffective as affinity ligands. The segments comprising both iduronate and glucuronate may serve as contact zones in the heparan sulfate/heparan sulfate self-association and the strength of binding is dependent on cooperative interactions between a number of such zones. The putative contact zones, as ligands on the matrix, showed an emerging lack of specificity as non-associating or unrelated and associating chains were bound to this gel. This is ascribed to a randomization of the contact zones which, in the polymeric chains, are placed in their proper register by the intervening (glucuronate-N-acetylglucosamine)n segments.

This publication has 13 references indexed in Scilit: