Mejia N R, MacKenzie R E
Department of Biochemistry, McGill University, Montreal, Que. Canada.
Biochem Biophys Res Commun. 1988 Aug 30;155(1):1-6. doi: 10.1016/s0006-291x(88)81040-4.
Transformed mammalian cells express a unique bifunctional NAD-dependent methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase in addition to the usual NADP-dependent dehydrogenase-cyclohydrolase-synthetase. Subcellular fractionation of murine cell lines revealed that the NAD-dependent dehydrogenase activity is located predominantly in mitochondria, while the NADP-dependent trifunctional dehydrogenase appears to exist only in the cytosol of these cells. Western analysis using monospecific polyclonal antisera confirms the subcellular distribution of these two proteins.
转化的哺乳动物细胞除了通常的依赖烟酰胺腺嘌呤二核苷酸磷酸（NADP）的脱氢酶-环水解酶-合成酶外，还表达一种独特的双功能依赖烟酰胺腺嘌呤二核苷酸（NAD）的亚甲基四氢叶酸脱氢酶-亚胺甲基四氢叶酸环水解酶。对小鼠细胞系进行亚细胞分级分离显示，依赖NAD的脱氢酶活性主要位于线粒体中，而依赖NADP的三功能脱氢酶似乎仅存在于这些细胞的胞质溶胶中。使用单特异性多克隆抗血清进行的蛋白质免疫印迹分析证实了这两种蛋白质的亚细胞分布。
