磁気共鳴を使った真核細胞内タンパク質の構造・機能解析

Abstract

Three-dimensional structures of proteins are often critical in understanding proteins functions. However, structures or states of proteins in cells undergo dynamical changes in response to interactions with other proteins and/or biological molecules. In addition, post-translational modification such as phosphorylation, methylation and ubiquitination can drastically change the structure and hence the properties of proteins. Therefore, to precisely correlate structure data of proteins with cell biology data, the structure information should be collected in living cells preferably at atomic level. In addition, as numerous biomolecules are packed into limited space, the concentration of macromolecules is substantially high in cells. Such crowded environment of the cell interior can markedly change proteins behavior, affecting biochemistry and biophysics of the proteins, which is so-called "Macromolecular Crowding Effect". To figure out protein behavior inside cells, which may be missed in in vitro studies, we are developing NMR and ESR methodologies to analyze protein structure and dynamics inside eukaryotic cultured cells. In this paper, in-cell NMR/ESR studies performed on HeLa cells and Xenopus oocytes are presented.