Increased heparin binding in cystic fibrosis: a reflection of altered glycoprotein biosynthesis?

Some of the serum proteins which bind to heparin and contribute to the pH 5.57 "heparin binding capacity" of human serum are glycoproteins; those from cystic fibrosis serum were found to be 27% higher in fucose (methylpentose) content, 27% lower in sialic acid content, and 31% lower in hexose content when compared to heparin-precipitated serum glycoproteins from normal control subjects. Hexosamine content of the heparin-precipitated serum glycoproteins was the same. Results of this preliminary investigation indicate that altered carbohydrate composition in serum glycoproteins may affect significantly their heparin binding capacity.