Narisawa K, Gibson K M, Sweetman L, Nyhan W L, Duran M, Wadman S K
J Clin Invest. 1986 Apr;77(4):1148-52. doi: 10.1172/JCI112415.
We studied two patients with 3-methylglutaconic aciduria in order to determine the molecular defect. A new assay for 3-methylglutaconyl-coenzyme A (CoA) hydratase has been developed in which the substrate, [5-14C]3-methylglutaconyl-CoA, was synthesized using 3-methylcrotonyl-CoA carboxylase purified from bovine kidney. In this assay the products of the reaction are isolated by reverse-phase high performance liquid chromatography and the rates of conversion from substrate are measured. The Michaelis constant for 3-methylglutaconyl-CoA in normal fibroblasts was 6.9 mumol/liter. The mean activity of 3-methylglutaconyl-CoA hydratase in control fibroblasts was 495 pmol/min per mg protein. In the two patients the values were 11 and 17 pmol/min per mg protein, or 2-3% of normal.
我们研究了两名患有3-甲基戊二酸尿症的患者，以确定分子缺陷。已开发出一种新的3-甲基戊二酰辅酶A（CoA）水合酶测定法，其中使用从牛肾中纯化的3-甲基巴豆酰辅酶A羧化酶合成底物[5-¹⁴C]3-甲基戊二酰辅酶A。在此测定法中，通过反相高效液相色谱法分离反应产物，并测量底物的转化速率。正常成纤维细胞中3-甲基戊二酰辅酶A的米氏常数为6.9微摩尔/升。对照成纤维细胞中3-甲基戊二酰辅酶A水合酶的平均活性为每毫克蛋白质495皮摩尔/分钟。两名患者的值分别为每毫克蛋白质11和17皮摩尔/分钟，即正常水平的2-3%。
