AJP - Lung Cellular and Molecular Physiology, Vol 260, Issue 4 326-L339, Copyright © 1991 by American Physiological Society
Immunological characterization of deglycosylated human and swine trachea and Cowper's gland mucin glycoproteins
S. Sangadala, J. M. Brewer and J. Mendicino
Department of Biochemistry, University of Georgia, Athens 30602.
Antibodies were raised in rabbits against purified swine and human trachea
and Cowper's gland mucin glycoproteins and their deglycosylated polypeptide
chains. Three monospecific antibody fractions that recognize the
carbohydrate, the deglycosylated or unglycosylated regions of the
polypeptide chains in these glycoproteins, were isolated by immunoaffinity
chromatography. The human and swine trachea mucin glycoproteins showed
extensive immunological homology in both their carbohydrate and polypeptide
chains. The carbohydrate chains and unglycosylated region of the
polypeptide chain in Cowper's gland mucin glycoprotein showed little or no
cross-reaction with comparable regions in respiratory mucin glycoproteins.
However, the polypeptide chains in the deglycosylated regions of all three
mucin glycoproteins showed extensive homology. Five bands with molecular
masses ranging from 40 to 46 kDa that differed by a constant molecular mass
of approximately 1.5 kDa were detected in hydrolysates of all of the
polypeptide chains after treatment with S. aureus V8 protease. Monospecific
antibodies to the deglycosylated region of these chains reacted with the
peptides, whereas those directed against the unglycosylated region did not.
The results suggest that these chains contain tandem repeating sequences of
amino acids.
