Abstract
A highly repetitive Mr=6.3×103 acidic glycan(G-6) of proteoglycan-like molecule mediates cell recognition and adhesion in the marine sponge Microciona prolifera. Specificity and sufficient adhesion strength is achieved through multiple binding of low affinity G-6 glycans to the cell surface receptors. This molecular mechanism is conceptually different from monovalent or tetravalent higher affinity interactions of adhesion and recognition molecules of immunoglobulin, cadherin, integrin and lectin families. The G-6 glycan is N-linked and contains glucuronic acid, fucose, mannose, galactose, N-acetyl glucosamine and sulfate. Such a unique composition indicates a novel type of structure with some features of glycosaminoglycans and N-linked polysaccharides.
