Cahill A, Cunningham C C
Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Electrophoresis. 2000 Oct;21(16):3420-6. doi: 10.1002/1522-2683(20001001)21:16<3420::AID-ELPS3420>3.0.CO;2-Q.
Chronic ethanol feeding has been shown to decrease the number of functionally active mitochondrial ribosomes by 55%. In this work, 55S mitochondrial ribosomes were isolated from rat liver and their constitutive proteins characterized by two-dimensional polyacrylamide gel electrophoresis and quantified by densitometry. A total of 86 proteins were found to be associated with the mitochondrial ribosome. This compares with 70 isolated from cytoplasmic ribosomes. In addition, mitochondrial ribosomal proteins were found to be significantly less basic than their cytoplasmic counterparts. Chronic ethanol feeding was found to significantly decrease the levels of a number of constitutive proteins of the mitochondrial ribosome when compared to those isolated from pair-fed controls. Sucrose density gradient analyses revealed a significant decrease in the number of intact 55S ribosomes. It is suggested that ethanol-elicited alterations in specific constitutive proteins of the mitochondrial ribosome may lead to impaired assembly of the monosome and that this may result in lower levels of those displaying functional activity.
长期喂食乙醇已被证明可使功能活跃的线粒体核糖体数量减少55%。在这项研究中，从大鼠肝脏中分离出55S线粒体核糖体，并用二维聚丙烯酰胺凝胶电泳对其组成蛋白进行表征，通过光密度法进行定量。共发现86种蛋白质与线粒体核糖体相关。相比之下，从细胞质核糖体中分离出70种蛋白质。此外，发现线粒体核糖体蛋白的碱性明显低于细胞质核糖体蛋白。与从配对喂食对照组分离出的线粒体核糖体组成蛋白相比，长期喂食乙醇会显著降低多种组成蛋白的水平。蔗糖密度梯度分析显示完整的55S核糖体数量显著减少。研究表明，乙醇引起的线粒体核糖体特定组成蛋白的改变可能导致单体组装受损，进而可能导致具有功能活性的核糖体水平降低。
