Wriessnegger T, Leitner E, Belegratis M R, Ingolic E, Daum G
Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, A-8010 Graz, Austria.
Biochim Biophys Acta. 2009 Mar;1791(3):166-72. doi: 10.1016/j.bbalip.2008.12.017. Epub 2009 Jan 10.
Here we describe for the first time isolation and biochemical characterization of highly purified mitochondrial inner and outer membranes from Pichia pastoris and systematic lipid analysis of submitochondrial fractions. Mitochondria of this yeast are best developed during growth on glycerol or sorbitol, but also on methanol or fatty acids. To obtain organelle membranes at high quality, methods of isolation and subfractionation of mitochondria originally developed for Saccharomyces cerevisiae were adapted and employed. A characteristic feature of the outer mitochondrial membrane of P. pastoris is the higher phospholipid to protein ratio and the lower ergosterol to phospholipid ratio compared to the inner membrane. Another marked difference between the two mitochondrial membranes is the phospholipid composition. Phosphatidylcholine and phosphatidylethanolamine are major phospholipids of both membranes, but the inner membrane is enriched in cardiolipin, whereas the outer membrane contains a high amount of phosphatidylinositol. The fatty acid composition of both mitochondrial membranes is similar. Variation of the carbon source, however, leads to marked changes of the fatty acid pattern both in total and mitochondrial membranes. In summary, our data are the first step to understand the P. pastoris lipidome which will be prerequisite to manipulate membrane components of this yeast for biotechnological purposes.
在此，我们首次描述了来自毕赤酵母的高度纯化的线粒体内膜和外膜的分离及生化特性，以及线粒体亚组分的系统脂质分析。这种酵母的线粒体在甘油或山梨醇上生长时发育最佳，但在甲醇或脂肪酸上生长时也能发育。为了获得高质量的细胞器膜，我们采用并调整了最初为酿酒酵母开发的线粒体分离和亚分级方法。与内膜相比，毕赤酵母线粒体外膜的一个特征是磷脂与蛋白质的比例较高，而麦角固醇与磷脂的比例较低。这两种线粒体膜之间的另一个显著差异是磷脂组成。磷脂酰胆碱和磷脂酰乙醇胺是两种膜的主要磷脂，但内膜富含心磷脂，而外膜含有大量的磷脂酰肌醇。两种线粒体膜的脂肪酸组成相似。然而，碳源的变化会导致总膜和线粒体膜中脂肪酸模式的显著变化。总之，我们的数据是了解毕赤酵母脂质组的第一步，这将是为生物技术目的操纵这种酵母膜成分的先决条件。
