Barańska J, Wojtczak L
Biochim Biophys Acta. 1984 Jun 13;773(1):23-31. doi: 10.1016/0005-2736(84)90546-7.
A protein fraction from rat liver cytoplasm, precipitable at 50-95% saturation of ammonium sulphate, binds phosphatidic acid from mitochondrial and microsomal membranes. Protein-bound phosphatidic acid was eluted from Sephadex G-75 in fractions corresponding to a molecular weight of about 10 000. No such binding was observed with mitochondrial soluble proteins, either total or precipitated with ammonium sulphate between 50 and 95% saturation. The transfer of phosphatidic acid from microsomes to mitochondria was increased by liver cytoplasmic proteins precipitable at 50-95% saturation of ammonium sulphate but not with mitochondrial soluble proteins. This increase by cytoplasmic proteins was pronounced in 200 mM sucrose but was negligible in 100 mM KCI where the spontaneous transfer was quite high. Cytoplasmic proteins stimulated the synthesis of cardiolipin and phosphatidylglycerol in mitochondria deprived of the outer membrane but not in intact mitochondria when phosphatidic acid was supplied either by microsomes or liposomes. It is suggested that the transfer of phosphatidic acid from the outer to the inner mitochondrial membrane is not mediated by transfer proteins but occurs either by direct contact of the membranes or as free diffusion through the aqueous phase.
一种来自大鼠肝脏细胞质的蛋白质组分，在硫酸铵饱和度为50 - 95%时可沉淀，它能结合线粒体和微粒体膜中的磷脂酸。与分子量约为10000相对应的组分从葡聚糖G - 75中洗脱得到结合了蛋白质的磷脂酸。无论是线粒体总可溶性蛋白还是在硫酸铵饱和度为50 - 95%时沉淀的线粒体可溶性蛋白，均未观察到这种结合现象。硫酸铵饱和度为50 - 95%时可沉淀的肝脏细胞质蛋白能增加磷脂酸从微粒体到线粒体的转移，但线粒体可溶性蛋白则不能。在200 mM蔗糖中，细胞质蛋白引起的这种增加很明显，但在100 mM KCl中可忽略不计，因为在100 mM KCl中自发转移相当高。当由微粒体或脂质体提供磷脂酸时，细胞质蛋白刺激了去除外膜的线粒体中心磷脂和磷脂酰甘油的合成，但对完整线粒体则无此作用。有人提出，磷脂酸从线粒体外膜向内膜的转移不是由转移蛋白介导的，而是通过膜的直接接触或通过水相自由扩散发生的。
