ROLE OF SIALIC-ACID ON THE VISCOSITY OF CANINE TRACHEAL MUCIN GLYCOPROTEIN

The role of sialic acid on the viscosity of canine tracheal mucin (CTM ) was investigated. The mucin glycoprotein, purified from canine trach eal mucus, was subjected to mild acid hydrolysis with aqueous acetic a cid and autohydrolysis in water, in which similar to 50% drop in the r elative viscosity (n(r)) occurred. Carbohydrate compositional analysis before and after mild acid hydrolysis and autohydrolysis showed the c omplete removal of glycosidically bound sialic acid residues while all other sugar residues (i.e. galactose, N-acetyl galactosamine and N-ac etyl glucosamine) remained unaltered, indicating that sialic acid resi dues are contributing towards the viscosity of CTM to a greater extent . (C) 1994 Academic Press, Tnc.