Electron microscopy of cervical, gastric and bronchial mucus glycoproteins.
Mucus glycoproteins (mucins) were obtained from human cervical and pig gastric mucus as well as from chronic-bronchitic sputum after low-shear extraction. The mucus gel was solubilized in guanidinium chloride supplemented with proteinase inhibitors, and the macromolecules were purified by using isopycnic density-gradient centrifugation. The macromolecules were spread in monolayers of benzyldimethylalkyl-ammonium chloride and studied with electron microscopy after staining with uranyl acetate and/or shadowing with platinum/carbon. The mucins appeared as flexible linear threads with lengths varying from approx. 200 nm to about 400 nm. No regularly branched or star-shaped structures were observed. The macromolecular architecture of cervical, respiratory and gastric mucins is thus similar.
D000818:Animals; D001980:Bronchi / Q000032:analysis*; D002237:Carbohydrate Dehydrogenases / Q000302:isolation & purification*; D002584:Cervix Uteri / Q000032:analysis*; D005260:Female; D005948:Glucose Dehydrogenases / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D009077:Mucins; D011487:Protein Conformation; D013270:Stomach / Q000032:analysis*; D013552:Swine
D046911:Macromolecular Substances; D009077:Mucins; D002237:Carbohydrate Dehydrogenases; D005948:Glucose Dehydrogenases; C033955:glucose dehydrogenase (pyrroloquinoline-quinone)