Poulos A, Beckman K
Clin Chim Acta. 1980 Feb 28;101(2-3):277-85. doi: 10.1016/0009-8981(80)90254-5.
The properties and bile salt specificities of galactosylceramide and lactosylceramide beta-galactosidase activities (GC and LC-beta-galactosidases) of human leucocytes and fibroblasts were compared. A number of differences were observed. Under the standard assay conditions the former activity was more sensitive to Zn2+ and Triton-X100. Glycocholate and cholate were more active stimulators of the GC-beta-galactosidase than the more frequently used taurocholate which was the most effective stimulator of LC-beta-galactosidase activity. It is postulated that some of the apparent differences in the properties of GC- and LC-beta-galactosidase activities may be attributed to the different micellar properties of the lipid substrates. Experiments with fibroblasts from patients with Krabbe's disease confirmed an almost total absence of GC-beta-galactosidase whichever bile acid was employed. Residual LC-beta-galactosidase activity detected in these cells was much higher ranging from 13% of the lowest measured value when measured with taurocholate to approximately normal values with glycocholate. Fibroblasts obtained from patients with GM1-gangliosidosis displayed close to normal GC and LC-beta-galactosidase activity under our experimental conditions. The data suggest that diagnoses of Krabbe's disease should be performed with galactosylceramide rather than lactosylceramide as substrate.
比较了人白细胞和成纤维细胞中半乳糖神经酰胺和乳糖神经酰胺β-半乳糖苷酶活性（GC和LC-β-半乳糖苷酶）的性质及胆汁盐特异性。观察到许多差异。在标准测定条件下，前者活性对Zn2+和Triton-X100更敏感。甘氨胆酸盐和胆酸盐对GC-β-半乳糖苷酶的刺激作用比更常用的牛磺胆酸盐更强，而牛磺胆酸盐是LC-β-半乳糖苷酶活性最有效的刺激剂。据推测，GC-和LC-β-半乳糖苷酶活性性质的一些明显差异可能归因于脂质底物不同的胶束性质。对克拉伯病患者的成纤维细胞进行的实验证实，无论使用何种胆汁酸，GC-β-半乳糖苷酶几乎完全缺失。在这些细胞中检测到的残余LC-β-半乳糖苷酶活性要高得多，用牛磺胆酸盐测量时为最低测量值的13%，用甘氨胆酸盐测量时接近正常值。在我们的实验条件下，从GM1神经节苷脂病患者获得的成纤维细胞显示出接近正常的GC和LC-β-半乳糖苷酶活性。数据表明，克拉伯病的诊断应以半乳糖神经酰胺而非乳糖神经酰胺为底物进行。
