Freeze H, Kress B C, Williams J C, Cerda-Ruiz M, Miller A L
Mol Cell Biochem. 1978 Oct 13;21(1):17-21. doi: 10.1007/BF00230192.
Mucolipidosis II (I-cell disease) and Mucolipidosis III (ML III) are inherited disorders in which the molecular defect may involve an abnormality in a common post-translational modification step (possibly glycosylation) shared by lysosomal hydrolases. We tested whether such an alteration might be a generalized defect in glycoprotein biosynthesis and, thus, be reflected in an abnormal carbohydrate composition of non-lysosomal glycoproteins. The apoprotein of low density lipoprotein (apo-LDL) and immunoglobulin G (IgG) were purified to apparent homogeneity. Gas liquid chromatographic (glc) analysis of the carbohydrate content of these glycoproteins from ML II, ML III and normal sera revealed no differences in the relative ratios and total amounts of mannose, galactose, N-acetylglucosamine and sialic acid. These results suggest that if the postulated post-translational defect in these disorders involves changes in carbohydrate composition, it is not a general defect in glycosylation and may be specific for lysosomal hydrolases.
黏脂贮积症II型（I型细胞病）和黏脂贮积症III型（ML III）是遗传性疾病，其分子缺陷可能涉及溶酶体水解酶共有的一个常见翻译后修饰步骤（可能是糖基化）异常。我们测试了这种改变是否可能是糖蛋白生物合成中的一种普遍缺陷，从而反映在非溶酶体糖蛋白的异常碳水化合物组成中。将低密度脂蛋白（apo-LDL）的载脂蛋白和免疫球蛋白G（IgG）纯化至表观均一。对来自ML II、ML III和正常血清的这些糖蛋白的碳水化合物含量进行气液色谱（glc）分析，结果显示甘露糖、半乳糖、N-乙酰葡糖胺和唾液酸的相对比例和总量没有差异。这些结果表明，如果这些疾病中假定的翻译后缺陷涉及碳水化合物组成的变化，那么它不是糖基化的普遍缺陷，可能是溶酶体水解酶特有的。
