Limulus polyphemus lectin sites in human bronchial mucosa.

The lectin from Limulus polyphemus (limulin) has an affinity for glycoproteins containing N-glycolyl or N-acetylneuraminic residues. By using a peroxidase labeled limulin on human bronchial mucosa sections, it has been possible to demonstrate selectively a diffuse staining within the apical part of the epithelial goblet cells. Whereas, in the submucosal glands serous cells, the labeling appears as small granules localized either at the apical pole or in the whole cytoplasm. In our experimental conditions the labeled limulin has no affinity for mucous cells that are known to contain sialic acid residues.