基于磁共振的胞浆中无标记酵母细胞色素c构象变化追踪

Track the Conformational Change of Unlabeled Yeast Cytochrome c in Cell Homogenate Using NMR

细胞色素c(cytochrome c,cyt c)是一个重要的多功能蛋白.在线粒体中,它作为载体传递电子.而在细胞质中,它可能会作为凋亡起始因子启动细胞凋亡程序.复杂的细胞质环境是否会对其构象产生影响,以及产生怎样的影响,目前仍然没有得到确证.本研究通过无标记的基于甲基的核磁共振(nuclear magnetic resonance,NMR)技术追踪了野生型酿酒酵母iso-1 cyt c在酵母细胞匀浆液中的构象变化.发现cyt c在细胞匀浆中至少存在4种不同的氧化态构象和1种还原态构象.而且随着时间的推进,不同构象之间发生转换.结果表明cyt c的构象会随环境改变,这可能与抵抗氧化应激相关.

Cytochrome c(cyt c)is an important multifunctional protein.In mitochondria,it acts as a carrier for electron transporting.In cytoplasm,it may act as an apoptotic initiator to initiate the apoptotic process.Whether and how a complex cytoplasmic environment affects its conformation has not been confirmed yet.In this study,the conformational changes of wild type saccharomyces cerevisiae iso-1 cyt c in yeast cell homogenate were tracked by methyl-based nuclear magnetic resonance(NMR)technique.At least four different oxidative conformations and one reduced conformation of cyt c were identified in cell homogenate.And over time,the transitions among different conformations of cyt c were observed.The results indicate that the conformation of cyt c changes with environment,which may be closely related to resistance to oxidative stress.