Binding of basic proteins to glycoproteins in human bronchial secretions.
1. Secretions were aspirated from a patient with no history of pulmonary disorder. 2. Mucus glycoproteins, which exhibited blood group A activity, were separated into cetyltrimethylammonium bromide (cetavlon)- and ethanol-precipitable fractions. 3. The cetavlon-precipitable mucin was pure by analytical ultracentrifugation and upon chemical analysis had a composition typical for mucin preparations. 4. The fraction that precipitated with ethanol was found to bind tightly to proteins of a basic nature from which it could be separated by using 6 M urea. 5. This non-covalent interaction may explain the lack of precipitation of this mucus glycoprotein by cetavlon. 6. These basic proteins may be important in determining the rheological behavior of mucociliary secretions.
D000293:Adolescent; D000596:Amino Acids / Q000032:analysis; D001980:Bronchi / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D009077:Mucins / Q000302:isolation & purification*; D009093:Mucus / Q000032:analysis*; D011485:Protein Binding
D000596:Amino Acids; D002241:Carbohydrates; D006023:Glycoproteins; D009077:Mucins