Isolation of a glycoprotein and proteodermatan sulphate from bovine achilles tendon by affinity chromatography on concanavalin A-Sepharose

Abstract

A fraction was isolated from a 3 M MgCl2 extract of bovine achilles tendon on the basis of its affinity for collagen. Affinity chromatography of this material on concanavalin A-Sepharose yielded a mixture which comprised a glycoprotein of approximate molecular weight 60 000 and two constituents containing hexuronic acid. The existence of a complex between the glycoprotein and material containing hexuronic acid was demonstrated by chromatography on Sephadex G-200 and by equilibrium sedimentation in CsCl density gradients. The complex was completely dissociated in 4 M guanidinium chloride. One of the constituents containing hexuronic acid was identified as a proteodermatan sulphate of low molecular weight and which had an abnormally high protein content (45-50%) and low buoyant density (1.46 g/ml) for a proteoglycan. The denser of the two molecules containing hexuronic acid appeared to be a normal proteoglycan, with a low protein content (11%). Analyses are given for the glycoprotein and the proteodermatan sulphate.