SOME OBSERVATIONS ON THE MOLECULAR FORM OF CHONDROITIN SULPHATE

Abstract

The physical properties of a preparation of chondroitin sulfate extracted from bovine cartilage with CaCl2 were measured at various stages of purification. After removal of free protein, the extract has a number-average molecular weight, from sedimentation and viscosity data, of about 1.0 x 10 2 . After tryptic digestion, the molecular weight of the extract was 39,000 on a number average basis and about 145,000 on a weight average basis from light scattering data. At both stages of purification, the extract was widely polydisperse and exhibited streaming birefringence in aqueous but not in salt solution. Before digestion, the particles evidently represented aggregates of polysaccharide molecules linked in an end-to-end arrangement by peptides; tryptic digestion partially destroyed these peptide linkages. It does not appear, from a partial analysis of the amino acids present, that the origin of the protein or peptide material was collagen.