RT Journal Article T1 Spectroscopic characterization and fusogenic propierties of pres domains of duck hepatitis B virus A1 Delgado, Carmen L. A1 Núñez, Elena A1 Yélamos, Belén A1 Gómez-Gutiérrez, Julián A1 Peterson, Darrell L. A1 Gavilanes, Francisco AB In order to shed light on the hepatitis B virus fusion mechanism and to explore the fusogenic capabilities of preS regions, a recombinant duck hepatitis B virus (DHBV) preS protein (DpreS) containing six histidines at the carboxyterminal end has been obtained. The DpreS domain, which has an open and mostly nonordered conformation as indicated by fluorescence and circular dichroism spectroscopies, has the ability to interact with negatively charged phospholipid vesicles. The observed interaction differences between neutral and acidic phospholipids can be interpreted in terms of an initial ionic interaction between the phospholipid polar headgroup and the protein followed by the insertion of probably the N-terminal region in the cellular membrane. Fluorescence polarization studies detect a decrease of the transition enthalpy together with a small modification of the transition temperature, typical effects of integral membrane proteins. The interaction of the protein with acidic phospholipid vesicles induces aggregation, lipid mixing, and leakage of internal contents, properties that have been ascribed to membrane destabilizing proteins. The fact that the preS domains of the hepadnaviruses have little similarity but share a very similar hydrophobic profile points to the importance of the overall three-dimensional structure as well as to its conformational flexibility and the distribution of polar and apolar amino acids on the expression of their destabilizing properties rather than to a particular amino acid sequence. The results presented herein argue for the involvement of DpreS in the initial steps of DHBV infection. Taken together with previously reported results, the conclusion that both S and preS regions participate in the fusion process of the hepadnaviridae family may be drawn. PB American Chemical Society SN 0006-2960; 1520-4995 YR 2012 FD 2012-10-09 LK https://hdl.handle.net/20.500.14352/44766 UL https://hdl.handle.net/20.500.14352/44766 LA eng NO Dirección General de Investigación y Gestión del Programa Nacional I+D+i of the Ministerio de Economía y Competitividad (Spain) NO Ministerio de Economía y Competitividad (MINECO) DS Docta Complutense RD 30 jul 2025