Influence of sialic acid on cell surface properties in I-cell disease fibroblasts.
Fibroblasts derived from patients with I-cell disease have been shown to accumulate many natural substrates including a three to fourfold increase in sialic acid content compared to that found in normal fibroblasts. This diverse accumulation of storage material is due to a massive deficiency of multiple lysosomal hydrolases as they are preferentially excreted into the culture fluid. There is evidence that the I-cell plasma membrane itself is abnormal with respect to certain transferase activities and in its sensitivity to freezing and Triton X-100. In this study, we have shown that a neuraminidase-sensitive substrate, and perhaps others in I-cell fibroblasts, contribute to an increased electronegativity if the I-cell fibroblast surface and to the cells' sensitivity to freezing. We also found that neuraminidase treatment of I-cell fibroblasts before preservative freezing in liquid nitrogen enables the cells to adapt more easily to subculture upon thawing.
D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism*; D004586:Electrophoresis; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D009081:Mucolipidoses / Q000378:metabolism*; D009439:Neuraminidase / Q000378:metabolism; D012794:Sialic Acids / Q000378:metabolism*
D012794:Sialic Acids; D009439:Neuraminidase