De Bruyn C H, Raymakers C, Wensing A, Oei T L
Clin Chim Acta. 1977 Jul 1;78(1):145-50. doi: 10.1016/0009-8981(77)90347-3.
When measuring with the spectrophotometric UDP-Glu consumption test, the galactose-1-phosphate uridyltransferase (Gal-PUT) activity in erythrocyte lysates from a 22-month-old infant with a late onset form of galactosemia was found to be approximately 25% of normal. With a radiochemical assay only a very low residual activity could be detected (+/- 1% of normal). Preincubation of the patient's lysate with purified NADase caused a marked decrease of residual Gal-PUT activity as judged from the data obtained with the consumption test. The radiochemical assay was not influenced by a similar pre-treatment. The high level of residual activity found with the consumption test in this patient was attributed to the consumption of UDP-Glu by other reactions than Gal-PUT. Because it is a direct, simple and generally applicable assay, the radiochemical procedure is suggested to be the best method for the more detailed enzymological characterisation of the Gal-PUT deficient state in galactosemics.
在用分光光度法测定UDP-葡萄糖消耗试验时，发现一名患有迟发性半乳糖血症的22个月大婴儿的红细胞裂解物中的1-磷酸半乳糖尿苷转移酶（Gal-PUT）活性约为正常水平的25%。采用放射化学测定法时，仅能检测到非常低的残余活性（约为正常水平的±1%）。根据消耗试验获得的数据判断，用纯化的NAD酶对患者的裂解物进行预孵育会导致Gal-PUT残余活性显著降低。放射化学测定不受类似预处理的影响。该患者消耗试验中发现的高水平残余活性归因于UDP-葡萄糖通过Gal-PUT以外的其他反应被消耗。由于放射化学方法是一种直接、简单且普遍适用的测定方法，因此建议将其作为对半乳糖血症患者Gal-PUT缺乏状态进行更详细酶学表征的最佳方法。
