Waheed A, Van Etten R L, Koob R, Drenckhahn D
Department of Chemistry, Purdue University, West Lafayette, IN.
Eur J Cell Biol. 1988 Feb;45(2):262-7.
Fibroblasts from I-cell disease, a genetically-determined lysosomal storage disease, are shown to contain large amounts of phase-dense lysosomes. These lysosomes accumulated acridine orange and were specifically labeled with antibodies to arylsulfatase A. In normal skin fibroblasts the number of arylsulfatase-containing lysosomes was considerably lower. By immunocytochemistry, metabolic labeling and enzyme assay, the arylsulfatase A in I-cell fibroblasts was shown to be synthesized, stored and secreted at a level that was several-fold higher than that present in heterozygous I-cell or normal fibroblasts. Arylsulfatase A in I-cell fibroblasts differed from arylsulfatase in normal fibroblasts by the absence of endoglycosidase H-sensitive phosphorylated oligosaccharides. These findings indicate that arylsulfatase A in I-cells is targeted to lysosomes by a mechanism that does not appear to involve the phosphorylated mannose marker.
来自I细胞病（一种由基因决定的溶酶体贮积病）的成纤维细胞显示含有大量电子密度高的溶酶体。这些溶酶体积累了吖啶橙，并被抗芳基硫酸酯酶A抗体特异性标记。在正常皮肤成纤维细胞中，含芳基硫酸酯酶的溶酶体数量要少得多。通过免疫细胞化学、代谢标记和酶测定，发现I细胞成纤维细胞中的芳基硫酸酯酶A在合成、储存和分泌水平上比杂合I细胞或正常成纤维细胞中的高几倍。I细胞成纤维细胞中的芳基硫酸酯酶A与正常成纤维细胞中的芳基硫酸酯酶不同，缺乏对内切糖苷酶H敏感的磷酸化寡糖。这些发现表明，I细胞中的芳基硫酸酯酶A通过一种似乎不涉及磷酸化甘露糖标记的机制靶向溶酶体。
