Rodríguez-Casado Arantxa, Molina Marina, Carmona Pedro
Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid, Spain.
Proteins. 2007 Jan 1;66(1):110-7. doi: 10.1002/prot.21192.
Electron microscopy and infrared and Raman spectroscopy have been used here to study the morphology, size distribution, secondary and tertiary structures of protein particles assembled from a truncated hepatitis C virus (HCV) core protein covering the first 120 aa. Particles of pure protein, having similar morphology and size distribution of those of nucleocapsids found in sera from HCV-infected patients, have been visualized for the first time. The secondary structure of these protein particles involve beta-sheet enrichment in relation to its protein monomer. Tertiary/quaternary structure has also been studied using the dynamics of H/D exchange. With this aim infrared spectra were measured as a function of H/D exchange time and subsequently analyzed by principal component analysis and two-dimensional correlation spectroscopy. Temporal dynamics of exchange for these protein particles were as follows: arginine residues exchanged first, followed by turn and unordered structures, followed by beta-sheets which may act as linkers of protein monomers.
本文利用电子显微镜、红外光谱和拉曼光谱研究了由覆盖前120个氨基酸的截短型丙型肝炎病毒（HCV）核心蛋白组装而成的蛋白质颗粒的形态、大小分布、二级和三级结构。首次观察到了纯蛋白质颗粒，其形态和大小分布与丙型肝炎病毒感染患者血清中的核衣壳相似。这些蛋白质颗粒的二级结构相对于其蛋白质单体富含β-折叠。还利用H/D交换动力学研究了三级/四级结构。为此，测量了作为H/D交换时间函数的红外光谱，随后通过主成分分析和二维相关光谱进行分析。这些蛋白质颗粒的交换时间动态如下：精氨酸残基首先发生交换，随后是转角和无序结构，接着是可能作为蛋白质单体连接体的β-折叠。
