Laboratory of food safety and molecular biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
PLoS One. 2012;7(3):e32943. doi: 10.1371/journal.pone.0032943. Epub 2012 Mar 5.
Grapefruit seed extract (GSE), which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and 4,6'-diaminidino-2-phenylindole (DAPI) staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential) and ROS (reactive oxygen species) indicated that the mitochondria took part in the apoptotic process. Changes in this process detected by metabonomics and proteomics revealed that the yeast cells tenaciously resisted adversity. Proteins related to redox, cellular structure, membrane, energy and DNA repair were significantly increased. In this study, the relative changes in the levels of proteins and metabolites showed the tenacious resistance of yeast cells. However, GSE induced apoptosis in the yeast cells by destruction of the mitochondrial 60 S ribosomal protein, L14-A, and prevented the conversion of pantothenic acid to coenzyme A (CoA). The relationship between the proteins and metabolites was analyzed by orthogonal projections to latent structures (OPLS). We found that the changes of the metabolites and the protein changes had relevant consistency.
葡萄柚籽提取物（GSE）具有强大的抗真菌活性，可诱导酿酒酵母细胞凋亡。通过检测 DNA 断裂和末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记（TUNEL）和 4,6'-二脒基-2-苯吲哚（DAPI）染色以及电子显微镜检查，确定酵母细胞发生了凋亡。线粒体跨膜电位（ΔΨmt）和活性氧（ROS）的变化表明线粒体参与了凋亡过程。代谢组学和蛋白质组学检测到的这一过程的变化表明酵母细胞顽强地抵抗逆境。与氧化还原、细胞结构、膜、能量和 DNA 修复相关的蛋白质显著增加。在这项研究中，蛋白质和代谢物水平的相对变化显示了酵母细胞的顽强抵抗能力。然而，GSE 通过破坏线粒体 60S 核糖体蛋白 L14-A 诱导酵母细胞凋亡，并阻止泛酸转化为辅酶 A（CoA）。通过正交投影到潜在结构（OPLS）分析了蛋白质和代谢物之间的关系。我们发现代谢物的变化与蛋白质变化具有相关性。
