Tsay G C, Dawson G, Matalon R
J Clin Invest. 1975 Sep;56(3):711-8. doi: 10.1172/JCI108142.
Patients with mannosidosis, an inherited deficiency of lysosomal alpha-mannosidase, accumulate large amounts of mannose-rich oligosaccharides (the "core" of the carbohydrate units of many glocoproteins) in brain and liver and excrete these partial degradation products in their urine. A profound alpha-mannosidase deficiency was demonstrated in fibroblasts cultured from a skin biopsy obtained from a child with mannosidosis. Further, abnormal glycopeptides rich in mannose and similar to oligosaccharides found in the patient's urine were isolated from fibroblast extracts by a variety of chromatographic procedures and by virtue of their binding to a concanavalin A-Sepharose 4B affinity column. This storage material contained mannose, N-acetylglucosamine, and asparagine in the ratio 3 : 1 : 1 together with a few toher amino acids and had a molecular weight of approximately 1,100. There was no evidence for excretion of storage material by mannosidosis fibroblasts or for any abnormality in cell surface glycoprotein composition. The glycopeptide nature of the storage material isolated from cultured skin fibroblasts may be attributed to the low level of N-aspartyl-beta-glucosamindase (EC 3.5.1.-) activity in these cells.
患有甘露糖苷贮积症（一种溶酶体α-甘露糖苷酶遗传性缺乏症）的患者，在脑和肝脏中积累大量富含甘露糖的寡糖（许多糖蛋白碳水化合物单元的“核心”），并在尿液中排泄这些部分降解产物。从一名患有甘露糖苷贮积症的儿童皮肤活检培养的成纤维细胞中证实存在严重的α-甘露糖苷酶缺乏。此外，通过各种色谱方法并借助它们与伴刀豆球蛋白A-琼脂糖4B亲和柱的结合，从成纤维细胞提取物中分离出富含甘露糖且与患者尿液中发现的寡糖相似的异常糖肽。这种储存物质含有甘露糖、N-乙酰葡糖胺和天冬酰胺，其比例为3:1:1，还含有一些其他氨基酸，分子量约为1100。没有证据表明甘露糖苷贮积症成纤维细胞会排泄储存物质，也没有证据表明细胞表面糖蛋白组成存在任何异常。从培养的皮肤成纤维细胞中分离出的储存物质的糖肽性质可能归因于这些细胞中N-天冬氨酰-β-葡糖胺酶（EC 3.5.1.-）活性水平较低。
