Burton B K, Ben-Yoseph Y, Nadler H L
Clin Chim Acta. 1978 Sep 15;88(3):483-93. doi: 10.1016/0009-8981(78)90283-8.
Neutral beta-galactosidase was partially purified from liver of normal controls, a patient with Niemann-Pick disease type A and the previously described patient with lactosyl ceramidosis using Concanavalin A-Sepharose adsorption and Sephadex G-100 gel filtration. The partially purified fractions were essentially free of galactosyl ceramide beta-galactosidase and GM1 beta-galactosidase activities. The normal and Niemann-Pick fractions were found to hydrolyze lactosyl ceramide, in the presence of sodium taurodeoxycholate, at a pH optimum of 5.6 as well as aryl beta-galactosides and aryl beta-glucosides at pH 6.2. The corresponding fraction from the lactosyl ceramidosis liver contained only 1--4% of the normal activity towards artificial substrates and lactosyl ceramide. Cross-reacting material identical to the normal was demonstrated in this fraction with antiserum raised against purified neutral beta-galactosidase, but no activity was observed in the precipitin line when stained with naphthol AS-LC-beta-galactoside or naphthol AS-LC-beta-glucoside. A similar deficiency of neutral beta-galactosidase activity was demonstrated in cultivated fibroblasts of the patient with lactosyl ceramidosis. Following adsorption on Concanavalin A-Sepharose and anti-GM1 beta-galactosidase antibody-Sepharose conjugates and chromatography on DEAE cellulose, fibroblast lysates from the patient exhibited 3% of normal activity towards 4-methyl-umbelliferyl beta-glucoside at pH 6.2 and 12% of normal activity towards lactosyl ceramide at pH 5.6. These data suggest that neutral beta-galactosidase may have an in vivo role in the cleavage of lactosyl ceramide and that a deficiency of this activity may be related to the lactosyl ceramide accumulation observed in the patient with lactosyl ceramidosis.
使用伴刀豆球蛋白A-琼脂糖吸附和葡聚糖凝胶G-100凝胶过滤法，从正常对照者肝脏、一名A型尼曼-匹克病患者肝脏以及先前描述的乳糖基神经酰胺沉积症患者肝脏中部分纯化中性β-半乳糖苷酶。部分纯化的组分基本不含半乳糖基神经酰胺β-半乳糖苷酶和GM1β-半乳糖苷酶活性。发现在牛磺去氧胆酸钠存在的情况下，正常和尼曼-匹克组分在pH值最适为5.6时能水解乳糖基神经酰胺，在pH值为6.2时能水解芳基β-半乳糖苷和芳基β-葡萄糖苷。来自乳糖基神经酰胺沉积症患者肝脏的相应组分对人工底物和乳糖基神经酰胺的活性仅为正常活性的1%至4%。用针对纯化的中性β-半乳糖苷酶产生的抗血清在该组分中证实了与正常物质交叉反应的物质，但用萘酚AS-LC-β-半乳糖苷或萘酚AS-LC-β-葡萄糖苷染色时，在沉淀线中未观察到活性。在乳糖基神经酰胺沉积症患者的培养成纤维细胞中也证实了中性β-半乳糖苷酶活性存在类似缺陷。在伴刀豆球蛋白A-琼脂糖和抗GM1β-半乳糖苷酶抗体-琼脂糖偶联物上吸附并在DEAE纤维素上进行层析后，患者的成纤维细胞裂解物在pH值为6.2时对4-甲基伞形酮基β-葡萄糖苷的活性为正常活性的3%，在pH值为5.6时对乳糖基神经酰胺的活性为正常活性的12%。这些数据表明，中性β-半乳糖苷酶可能在体内对乳糖基神经酰胺的裂解中起作用，并且这种活性的缺乏可能与乳糖基神经酰胺沉积症患者中观察到的乳糖基神经酰胺积累有关。
