Identification and synthetic pathway of sialyl-Lewisx-containing neolacto-series gangliosides in lens tissues. 1. Characterization of gangliosides in human senile cataractous lens.

Human lens accumulates gangliosides in association with aging and senile cataract progression. In this study we purified and characterized five major gangliosides in human cataractous lenses. Structural analyses and immunological studies revealed the presence of ganglio-series gangliosides, GM3, GM2, GM1 and GD1a, and a sialyl-Lewisx-containing neolacto-series ganglioside, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1ceramide (IV3NeuAcIII3FucnLc4). Slow-moving gangliosides, although minor components, were also found to have sialyl-Lewisx-related structures, based on anti-Lewisx antiserum binding to their asialo forms. However, sialyl-paragloboside, a possible precursor of the sialyl-Lewisx ganglioside, was not identified.