Barash V, Khassis S, Granat M, Gutman A
Department of Clinical Biochemistry, Hadassah University Hospital, Jerusalem, Israel.
Enzyme. 1988;39(1):54-9. doi: 10.1159/000469094.
Pyruvate carboxylase (PC) activity was assayed in 27 chorionic villi samples (CVS) obtained at 9-12 weeks of gestation. The kinetic properties of the CVS enzyme were similar to those of liver PC; more than 75% of PC activity was recovered in the mitochondrial fraction of CVS. Apparent Km for pyruvate, ATP, acetyl CoA and HCO3- in the presence of saturation concentrations of the other reactants, were 0.3, 0.44, 0.015 and 6.0 mmol/l, respectively. The optimum pH was 7.5-8.0. The activity of PC in CVS was 3.2 +/- 0.3 nmol/min/mg protein, which is severalfold higher than that of amniotic fluid fibroblasts.
在妊娠9至12周获取的27份绒毛膜绒毛样本（CVS）中检测了丙酮酸羧化酶（PC）活性。CVS酶的动力学特性与肝脏PC相似；超过75%的PC活性存在于CVS的线粒体部分。在其他反应物饱和浓度存在的情况下，丙酮酸、ATP、乙酰辅酶A和HCO3-的表观Km分别为0.3、0.44、0.015和6.0 mmol/L。最适pH为7.5 - 8.0。CVS中PC的活性为3.2 +/- 0.3 nmol/分钟/毫克蛋白质，比羊水成纤维细胞的活性高几倍。
