Intrinsic structural versatility of the highly conserved 412-423 epitope of the Hepatitis C Virus E2 protein(144 visite) Balasco N, Barone D, Iaccarino E, Sandomenico A, De Simone A, Ruvo M, Vitagliano L
*** IBB - CNR *** Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy. Electronic address: firstname.lastname@example.org., Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy; Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Universita della Campania "Luigi Vanvitelli", Caserta 81100, Italy., Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK., Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy. Electronic address: email@example.com.,
HCV infection is a major threaten for human health as it affects hundreds of million people worldwide. Here we investigated the conformational properties of the 412-423 fragment of the envelope E2 protein, one of the most immunogenic regions of the virus proteome whose characterization may provide interesting insights for anti-HCV vaccine development. The spectroscopic characterization of the polypeptide unravels its unexpected tendency to form amyloid-like aggregates. When kept in monomeric state, it shows a limited tendency to adopt regular secondary structure. Enhanced molecular dynamics simulations, starting from four distinct conformational states, highlight its structural versatility. Interestingly, all multiform conformational states of the polypeptide detected in crystallographic complexes with antibodies are present in the structural ensemble of all simulations. This observation corroborates the idea that known antibodies recognize this region through a conformational selection mechanism. Accordingly, the design of effective anti-HCV vaccines should consider the intrinsic flexibility of this region. The structural versatility of the 412-423 region is particularly puzzling if its remarkable sequence conservation is considered. It is likely that flexibility and sequence conservation are important features that endow this epitope with the ability to accomplish distinct functions such as immunity escape and interaction with host receptors.