Low Buoyant Density Proteoglycans from Saline and Dissociative Extracts of Embryonic Chicken Retinas

摘要: Abstract: Retinas were labeled in culture with [3H]glucosamine or [3H]leucine and [35S]sulfate extracted sequentially physiologically balanced saline 4 M guanidine HCl. They dialyzed into associative conditions (0.5 NaCl) chromatographed on agarose columns. Under these conditions, some of the proteoglycans associated massive complexes that showed low buoyant densities when centrifuged CsCl density gradients under dissociative (4 HCl). Much label was molecules other than proteoglycans. Most proteoglycans, however, included columns, where they appeared to be constitutionally density. resisted attempts separate potential contaminants from major by direct gradient centrifugation fractionation 8 urea extracts diethylaminoethyl-Sephacel. The diethylaminoethyl-Sephacel fractions either subjected Sephacryl S-300, both cases before after alkaline cleavage, confirm presence typical O-linked glycosaminoglycans. medium salt enriched chondroitin sulfate sul-fated macromolecules, possibly highly sulfated oligosaccharides, digestion chondroitinase ABC but electrophoretically less mobile heparan sulfate. Guanidine HCl residues mixtures high