Further observations on the glycoproteins in human ovarian cyst fluids

Abstract

An examination has been made of a number of ovarian cyst fluid glycoproteins that are sparingly soluble water but are similar in general composition to the readily soluble blood-group specific glycloproteins obtained from the same source. Ultracentrifugal analysis of approx. 0.1% w/v solutions of the sparingly soluble materials indicate that they have much larger sedimentation coefficients (S_20,w) and molecular weights than have the water-soluble glycoproteins. The sparingly soluble substances have more total amino acids and proportionally more aspartic and glutamic acids and cystine and less serine and threonine than have the soluble glycoproteins. The sparingly soluble substances mostly dissolve in buffered (pH 6.8–7.0, 0.05 M) solutions of thioglycolate, sulphite or cysteine, reagents that bring about the scission of -S-S-bonds. The behaviour and properties of the sparingly soluble glycoproteins suggest that they arise through the building up of relatively small glycoproteins to larger macromolecules through the formation of -S-S- intermolecular associations. A number of ways whereby the formation of these sparingly soluble glycoproteins could occur are discussed.