Localization of antigenic components in proteoglycan aggregate of bovine nasal cartilage

Proteoglycans and glyco(link)proteins are demonstrated in the cartilage matrix using immunohistochemical reactions, ruthenium red staining and concanavalin A-peroxidase procedure. Specific antibodies against proteoglycan monomers revealed a loose matrix structure in the interterritorial area of nasal cartilage. Thin filaments of 49-87 nm in length with a knob on one end corresponding to the protein core of proteoglycan monomers were found in irregular contacts with collagen fibres. Following hyaluronidase digestion the immunohistochemical reactions became more intense, and the matrix structure is suggestive of a network of single filaments which are presumably coupled together longitudinally at the sites of small matrix granules. These matrix granules proved to be glyco(link)proteins of proteoglycan aggregate. Immunohistochemical reactions combined with other methods can reveal an in situ structure of proteoglycan aggregate of hyaline cartilage, which contributes substantially to what has been known about the proteoglycan aggregates on the basis of physico-chemical data and has been verified in monomolecular electron microscopic specimens. The enzymatic treatments of cartilage slices suggest that some of the partially digested proteoglycan monomers are required to be present for the preservation of the structural integrity of cartilage tissue.