A segment of the cartilage proteoglycan core protein has lectin-like activity

Abstract

A segment of 130 residues near the COOH terminus of the proteoglycan core protein derived from rat cartilage is highly homologous to the carbohydrate-recognition domain of the chicken hepatic lectin and other vertebrate carbohydrate-binding proteins. This portion of the protein has been expressed in an in vitro transcription and translation system and has been tested for its ability to interact with carbohydrates using affinity chromatography on immobilized sugars. A distinct specificity of the binding interaction is demonstrable, with fucose and galactose being the preferred ligands. However, the affinity of the expressed domain of the proteoglycan core protein is lower than that of the other known binding domains, since it elutes from the columns even in the presence of Ca2+.