FRACTIONATION IN A DENSITY GRADIENT OF SOME GLYCOPROTEINS FROM HUMAN OVARIAN CYST FLUIDS

Equilibrium density gradient sedimentation in caesium chloride has been used as an effective method of separating the components of sulphite‐reduced sparingly soluble glycoproteins from two human ovarian cyst fluids. An almost quantitative recovery of the carbohydrate and peptide constituents has been obtained. Some fractions had overall chemical compositions similar to those isolated previously by Dunstone and Morgan in 1965, while others contained much greater proportions of amino acids, especially of aspartic acid, glutamic acid and cystine. The results suggest that the sparingly soluble glycoproteins are large macromolecules containing serologically active carbohydrate chains, bound to specific peptide fragments which form an integral part of larger macromolecules, the insolubility of which is due to the presence of –S‐S‐bonds. The experiments emphasize the value of equilibrium density gradient sedimentation in the study of complex proteinpolysaccharide systems. Copyright © 1969, Wiley Blackwell. All rights reserved