Spectroscopic study of conformational changes accompanying self-assembly of HCV core protein.
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.
Rodríguez-Casado
Arantxa
A
Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid, Spain.
Molina
Marina
M
Carmona
Pedro
P
D001120:Arginine / Q000378:metabolism; D002942:Circular Dichroism; D041961:Deuterium Exchange Measurement; D019281:Dimerization; D008854:Microscopy, Electron; D008958:Models, Molecular; D019251:Nucleocapsid / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014758:Viral Core Proteins / Q000737:chemistry* / Q000378:metabolism; D019065:Virus Assembly
D011994:Recombinant Proteins; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus; D001120:Arginine