title: The presence of a reduced amount of 32-kd "protective" protein is a distinct biochemical finding in late infantile galactosialidosis.
abstract: The biochemical defect underlying the late infantile form of galactosialidosis has been investigated in fibroblasts from two patients presenting with this phenotype. Immunoprecipitation experiments demonstrated that a reduced amount of 32-kd "protective" protein and a normal amount of its precursor are present in late infantile galactosialidosis fibroblasts, while neither of the two polypeptides are detectable in early infantile and juvenile/adult fibroblasts. Leupeptin treatment led to a slight increase in the amount of 54-kd and 32-kd polypeptides in both late-infantile galactosialidosis cell lines. Uptake studies in one of the two cell lines confirmed the hypothesis that a block in the maturation of the protective protein is responsible for the late infantile type of galactosialidosis. This mutation seems to be a distinct finding in all patients affected by this form of the disease.
mesh_terms: D002239:Carbohydrate Metabolism, Inborn Errors / Q000235:genetics*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000032:analysis; D005696:Galactosidases / Q000172:deficiency*; D006801:Humans; D007223:Infant; D007976:Leupeptins; D008970:Molecular Weight; D009439:Neuraminidase / Q000172:deficiency*; D011506:Proteins / Q000235:genetics*; D001616:beta-Galactosidase / Q000172:deficiency*
chemical_list: D007976:Leupeptins; D011506:Proteins; D005696:Galactosidases; D009439:Neuraminidase; D001616:beta-Galactosidase; C032854:leupeptin