title: Immunochemical analysis of cartilage proteoglycans. Radioimmunoassay of the molecules and the substructures.
abstract: Antibodies specifically reacting with the link proteins, the hyaluronic acid-binding region and chondroitin sulphate-peptides were used to design specific radioimmunoassay procedures. The sensitivity of the method used for the link protein was about 20 ng/ml, and the other two components could be determined at concentrations of about 2 ng/ml. The radioimmunoassay procedures were tested by using proteoglycan subfractions or fragments thereof. The procedures used to quantify link protein and hyaluronic acid-binding region showed no cross-interference. Fragments of trypsin-digested proteoglycan monomers still reacted in the radioimmunoassay for hyaluronic acid-binding region. Subfractions of proteoglycan monomers separated according to size had a gradually higher relative content of the hyaluronic acid-binding region compared with both chondroitin sulphate-peptides and uronic acid, when the molecules were smaller. The proteoglycans therefore may contain a variably large chondroitin sulphate-rich region, which has a constant substitution with polysaccharide side chains.
mesh_terms: D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex / Q000032:analysis; D002356:Cartilage / Q000032:analysis*; D002809:Chondroitin Sulfates / Q000032:analysis; D003429:Cross Reactions; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000032:analysis; D011509:Proteoglycans / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods; D014357:Trypsin
chemical_list: D000906:Antibodies; D000936:Antigen-Antibody Complex; D046911:Macromolecular Substances; D010446:Peptide Fragments; D011509:Proteoglycans; D002809:Chondroitin Sulfates; D014357:Trypsin