Heterogeneity of lysosomal enzymes in cultured normal and sialidosis type II human fibroblasts and the effect of ammonium chloride on this heterogeneity.

Lysosomal enzymes of human skin fibroblasts sediment in a Percoll gradient with major peaks at 1.05 and 1.10 g cm-3. The distribution of enzyme activity between the two peaks is dependent on growth state of the cells. Sialidosis Type II fibroblasts show a normal distribution pattern. NH4Cl stimulates enzyme secretion and de novo enzyme synthesis.