Characterization of mucin-type oligosaccharides with the sialyl-Le(a) structure from human colorectal adenocarcinoma cells.

Oligosaccharides with the sialyl-Le(a) structure have been isolated on an affinity column of a monoclonal antibody, MSW 113, from mucin-type glycoproteins derived from the surfaces of SW 1116 and LS 180 cells, and their secretions. The oligosaccharides were polydisperse with respect to molecular size, the oligosaccharides derived from glycoproteins in culture media being larger than those in cell lysates, as assessed by gel filtration. Some of the oligosaccharides were susceptible to degradation by endo-beta-galactosidase (E. freundii), as judged from the change in the gel filtration pattern. These results indicate that oligosaccharides with the sialyl-Le(a) structure derived from mucin-type glycoproteins produced by human colonic cancer cells are extremely large in size and complex in structure, and that some of them contain the poly-N-acetyllactosamine structure.