Isolation and characterization of the heparan sulfate proteoglycans of brain. Use of affinity chromatography on lipoprotein lipase-agarose.
Heparan sulfate proteoglycans were extracted from rat brain microsomal membranes or whole forebrain with deoxycholate and purified from accompanying chondroitin sulfate proteoglycans and membrane glycoproteins by ion-exchange chromatography, affinity chromatography on lipoprotein lipase-Sepharose, and gel filtration. The proteoglycan has a molecular size of approximately 220,000, containing glycosaminoglycan chains of Mr = 14,000-15,000. In [3H]glucosamine-labeled heparan sulfate proteoglycans, approximately 22% of the radioactivity is present in glycoprotein oligosaccharides, consisting predominantly of N-glycosidically linked tri- and tetraantennary complex oligosaccharides (60%, some of which are sulfated) and O-glycosidic oligosaccharides (33%). Small amounts of chondroitin sulfate (4-6% of the total glycosaminoglycans) copurified with the heparan sulfate proteoglycan through a variety of fractionation procedures. Incubation of [35S]sulfate-labeled microsomes with heparin or 2 M NaCl released approximately 21 and 13%, respectively, of the total heparan sulfate, as compared to the 8-9% released by buffered saline or chondroitin sulfate and the 82% which is extracted by 0.2% deoxycholate. It therefore appears that there are at least two distinct types of association of heparan sulfate proteoglycans with brain membranes.
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D000362:Agar; D000818:Animals; D001923:Brain Chemistry; D002499:Centrifugation, Density Gradient; D011508:Chondroitin Sulfate Proteoglycans / Q000302:isolation & purification*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D006025:Glycosaminoglycans / Q000302:isolation & purification*; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000302:isolation & purification*; D008071:Lipoprotein Lipase / Q000378:metabolism; D008970:Molecular Weight; D011509:Proteoglycans / Q000302:isolation & purification*; D051381:Rats; D011919:Rats, Inbred Strains
D000362:Agar; D011508:Chondroitin Sulfate Proteoglycans; D006025:Glycosaminoglycans; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D008071:Lipoprotein Lipase; D011509:Proteoglycans