A sensitive assay for active link protein from cartilage.
A new assay for the activity of cartilage link protein is described. The method is based on the finding [Plaas, Sandy & Muir (1983) Biochem. J. 214, 855-864] that addition of link protein to [35S]sulphate-labelled proteoglycan aggregates from rabbit chondrocyte cultures resulted in the formation of link-stabilized aggregates. The percentage aggregate was found to be related linearly to the amount of purified bovine link protein added in the 20-120 ng range. The assay was used to monitor loss of link-protein activity during heat denaturation and to measure binding of link protein by purified proteoglycan monomer.
D000818:Animals; D002358:Cartilage, Articular / Q000032:analysis*; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins; D006358:Hot Temperature; D046911:Macromolecular Substances; D008722:Methods; D011485:Protein Binding; D011489:Protein Denaturation; D011506:Proteins / Q000032:analysis*; D011509:Proteoglycans; D011817:Rabbits; D000099249:Proteoglycan Link Protein
D016326:Extracellular Matrix Proteins; D046911:Macromolecular Substances; D011506:Proteins; D011509:Proteoglycans; D000099249:Proteoglycan Link Protein