A comparative study of the accumulated sialic acid-containing oligosaccharides from cultured human galactosialidosis and sialidosis fibroblasts.

Sialic acid-containing storage material was isolated from cultured human galactosialidosis fibroblasts, by a combination of gel filtration and anion-exchange chromatography on Mono Q. The obtained sialyloligosaccharides were analyzed by 500-MHz 1H-NMR spectroscopy in combination with sugar analysis and analytical HPLC. The storage material consisted of a series of completely sialylated N-acetyl-lactosamine type of structures having Man beta 1-4GlcNAc at the reducing terminus in common, similar to those recently reported for human sialidosis fibroblasts. Comparison of the storage material from both sources revealed only differences in their relative amounts. In control fibroblasts these compounds could not be detected. The nature of the accumulated compounds is in accordance with the alpha-neuraminidase deficiency in both genetic diseases. The additional deficiency of beta-galactosidase in case of galactosialidosis is not reflected in the storage material.