Ornstein K S, McGuire E J, Berry G T, Roth S, Segal S
Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia.
Pediatr Res. 1992 May;31(5):508-11. doi: 10.1203/00006450-199205000-00020.
An abnormality in galactosylation of complex carbohydrates may be important in the pathogenesis of the long-term complications of classic (galactose-1-phosphate uridyltransferase-deficient) galactosemia. The ability of nine galactosemic fibroblast preparations to be galactosylated with a purified galactosyltransferase was measured as an indicator of vacant sites where galactose would normally reside. The amount of galactose transferred to cell protein from galactosemic patients was significantly higher than that transferred to a group of seven controls (p less than 0.005). Galactosyltransferase activity of the galactosemic cell preparation toward N-acetylglucosamine was also significantly higher than normal (p less than 0.01), and there was a linear relationship between these two parameters in galactosemic but not normal cells. These findings suggest that there is defective galactosylation of galactosemic cell complex carbohydrates and that such cells increase their galactosyltransferase levels in an attempt to compensate for the defect. Defective galactosylation may be implicated as an etiologic factor in complications observed in galactosemic patients even when treated with galactose-restricted diets.
复合碳水化合物半乳糖基化异常可能在典型（1-磷酸半乳糖尿苷酰转移酶缺乏型）半乳糖血症的长期并发症发病机制中起重要作用。测定了九份半乳糖血症成纤维细胞制剂用纯化的半乳糖基转移酶进行半乳糖基化的能力，以此作为半乳糖正常存在的空位指标。从半乳糖血症患者细胞蛋白转移来的半乳糖量显著高于从七名对照组患者转移来的量（p<0.005）。半乳糖血症细胞制剂对N-乙酰葡糖胺的半乳糖基转移酶活性也显著高于正常水平（p<0.01），并且在半乳糖血症细胞而非正常细胞中，这两个参数之间存在线性关系。这些发现表明，半乳糖血症细胞复合碳水化合物的半乳糖基化存在缺陷，并且此类细胞会提高其半乳糖基转移酶水平以试图弥补该缺陷。即使对半乳糖血症患者采用限制半乳糖饮食治疗，半乳糖基化缺陷也可能是观察到的并发症的病因。
