Inyangetor P T, Thierry-Palmer M
Department of Biochemistry, Morehouse School of Medicine, Atlanta, Georgia 30310-1495.
Arch Biochem Biophys. 1988 May 1;262(2):389-96. doi: 10.1016/0003-9861(88)90389-x.
Metabolism of vitamin K1 in rat liver mitochondria has been studied with succinate as the source of reducing equivalents. A metabolite was isolated that comigrated with vitamin K1 epoxide using four different chromatographic systems. The purified metabolite had an ultraviolet spectrum (200-330 nm) that was identical to that of synthetic vitamin K1 epoxide. The mass spectrum of the purified metabolite was identical to that of synthetic vitamin K1 epoxide. A comparison of production of vitamin K1 epoxide by mitochondrial and microsomal preparations indicates that the mitochondrial production of vitamin K1 epoxide was about 50% of that of the microsomes. Since the mitochondrial preparation was found to have only 3.4% of the glucose-6-phosphatase activity of the microsomal preparation, it can be concluded that the vitamin K1 epoxide isolated from the mitochondrial incubations was due primarily to mitochondrial synthesis. Epoxidation of vitamin K1 in mitochondria suggests that mitochondria might be sites for vitamin K-dependent carboxylation of protein(s).
以琥珀酸作为还原当量的来源，对大鼠肝线粒体中维生素K1的代谢进行了研究。分离出一种代谢物，在四种不同的色谱系统中，该代谢物与维生素K1环氧化物的迁移率相同。纯化后的代谢物具有与合成维生素K1环氧化物相同的紫外光谱（200 - 330nm）。纯化后代谢物的质谱与合成维生素K1环氧化物的质谱相同。线粒体和微粒体制剂产生维生素K1环氧化物的比较表明，线粒体产生的维生素K1环氧化物约为微粒体的50%。由于发现线粒体制剂的葡萄糖-6-磷酸酶活性仅为微粒体制剂的3.4%，可以得出结论，从线粒体培养液中分离出的维生素K1环氧化物主要是由于线粒体合成。线粒体中维生素K1的环氧化表明线粒体可能是蛋白质维生素K依赖性羧化的场所。
