The cellular uptake of N-acetyl-α-D-glucosaminidase, the deficient enzyme in Sanfilippo B disease, and the intracellular fate and metabolic effect of this enzyme have been investigated in Sanfilippo B and normal fibroblasts. For both genotypes the uptake is highly efficient (up to 0.025 mU/h/mg cell protein), specific and constant over a period of at least 6 days. It is probable that the enzyme protein is taken up by adsorptive pinocytosis. The enzymatic activity as well as the biological activity towards 35SO4-labeled mucopolysaccharides persist in Sanfilippo B cells with a half-life of 34 h, indicating the intralysosomal localization of the pinocytosed enzyme.
K. von Figura, H. Kresse
85 | 86 | 87 | 88 | 89 | 90 |