Isolation and characterization of polyfucosylated lactosaminoglycan from human granulocytes.

Lactosaminoglycan was isolated from human granulocytes and the structure of neutral lactosaminoglycan was elucidated. The lactosaminoglycan glycopeptides and lactosaminoglycan saccharides obtained by hydrazinolysis were analyzed by permethylation. In addition, the lactosaminoglycan was digested by endo-beta-galactosidase and the "core" portion and released oligosaccharides were analyzed by specific glycosidases, permethylation, and fast atom bombardment mass spectrometry. The structure of the major component in the neutral lactosaminoglycan was found to be: sequence in text where m + n + o + p greater than 6, and the mean value of fucose content = 4.5. This structure is unique in that 1) four linear polylactosaminyl chains are attached to the core portions, 2) N-acetylglucosamine residues in the polylactosaminyl side chains are substituted with fucose through an alpha 1----3 linkage and at least 1 mol of Gal beta 1----4(Fuc alpha 1----3)GlcNAc terminal structure is present, and 3) the tetraantennary core is a major component. Since this polyfucosylated lactosaminoglycan is abundantly present in human granulocytes, we propose that this lactosaminoglycan is a major carrier for the granulocyte-specific antigen, Gal beta 1----4(Fuc alpha 1----3)GlcNAc, which is recognized by the My-1 monoclonal antibody (Huang, L. C., Civin, C. I., Magnani, J. L., Shaper, J. H., and Ginsburg, V. (1983) Blood 61, 1020-1023).