HCVc 120 is a truncated protein from the hepatitis C virus (HCV) core protein that interacts with itself to form nucleocapsid-like particles. We present here the infrared and Raman spectra of oligomeric HCVc 120 protein in order to obtain insights into its secondary structure as well as the environment surrounding some protein side chains. When compared with its monomer form, oligomeric HCVc 120 protein shows an increase in beta-sheet structure. Tryptophan residues have been found to be solvent exposed in the oligomeric form, and they likely do not significantly participate in the protein assembly. However, the beta-sheet content in oligomeric HCVc 120 protein suggests that this structural motif cannot be excluded in nucleocapsid formation, as shown recently in other viruses.
(c) 2006 Wiley Periodicals, Inc.