Human respiratory tract secretion. Mucous glycoproteins of nonpurulent tracheobronchial secretions, and sputum of patients with bronchitis and cystic fibrosis.

Mucous glycoproteins were isolated by agarose gel filtration from nonpurulent tracheobronchial secretions 
and purulent sputum which had been reduced, carboxymethylated and, in the 
case of purulent secretions, treated with deoxyribonuclease. The solubilized and purified 
glycoproteins were fractioned on diethylaminoethyl cellulose into two major (I, II) 
and two minor (Ia, III) blood group active components. Components I 
and II had similar carbohydrate and amino acid compositions which were 
typical for human blood group substances. These two components did differ 
in several respects. Component I contained 1.4-2.6% sulfate and did not 
inhibit influenza virus hemagglutination while component II contained 7.1-7.8% sulfate and 
was a potent inhibitor of virus hemagglutination. Component II also migrated 
more rapidly on sodium dodecyl sulfate-3.3% acrylamide gel electrophoresis. Components I 
and II in purulent secretions displayed only minor compositional differences from 
their counterparts in nonpurulent secretions. Component II was more abundant in 
two sputum samples from subjects with cystic fibrosis than in purulent 
bronchitic secretions or in nonpurulent secretions. 