Analysis of site-dependent mucins in rat intestinal mucosa using anti-glycan monoclonal antibodies.

Intestinal gel-forming mucins are high-molecular weight glycoproteins, and their glycan moieties vary depending on the intestinal site. Although the means of analyzing mucin glycans are limited, monoclonal antibodies are expected to be a powerful analysis tool. In this study, 12 monoclonal antibodies were generated using rat intestinal mucin as the immunogen, and the epitopes of the antibodies were studied. The analyses using resins with the glycans of blood group-associated antigens and neoglycolipids synthesized from mucin glycans revealed that most antibodies recognize glycans. Furthermore, some recognize blood group-related antigens on glycans, whereas others recognize immaturely synthesized mucin-type glycans. Immunostaining of the rat jejunum, ileum, proximal colon, and distal colon with antibodies produced a site-dependent staining intestinal image. Affinity chromatography using an antibody-conjugated column was utilized to fractionate rat small intestinal mucins. Mucins with various glycan compositions were produced, suggesting the possibility of obtaining site-specific mucins. The site-specific mucins with various glycan compositions result in site-specific glycan functions, and the antibodies developed in this study could be useful tools for their analysis.