Research Information System
HIBIT2024 (17th International HIBIT Conference), İstanbul, Turkey, 18 - 20 December 2024, pp.104, (Summary Text)
Hepatitis, a form of liver damage prevalent worldwide, including in Turkey, can be caused by both viral and non-viral agents. A significant viral cause is the Hepatitis B virus (HBV), a double-stranded DNA virus from the Hepadnaviridae family. Despite the availability of safe hepatitis B vaccines for all age groups, cases of incomplete vaccine eÉicacy and immune escape variants still persist. Although vaccines based on the surface antigens of the Hepatitis B virus are widely available, the threedimensional (3D) structures of these proteins are still lacking. In this study, local, global, and multiple sequence alignment algorithms were applied for protein sequence analyses, prediction of consensus modeling candidates, and selection of immune escape variants. Homologous sequences for HBV S and M proteins were identified using BLASTp against the non-redundant protein database, and if available, structures were retrieved from the Protein Data Bank (PDB). These served as templates for 3D modeling of the Hepatitis B surface antigen (HBsAg). Candidate proteins were modeled using AlphaFold and I-TASSER. Protein sequence and structural features were calculated using various computational biology tools for both models. The KyteDoolittle scale was applied to assess protein hydrophobicity, and the Grand Average of Hydropathy (GRAVY) values were calculated. Additionally, the hydrophobic moments (surface polarities) of the proteins were determined using the 3D Hydrophobic Moment Vector Calculator (3D-HM). Surface electrostatics were calculated with PyMOL. A comparative analysis of the structures and structural features as well as quality metrics were performed to gain a deeper understanding of the immune escape variants. These findings enhance our understanding of the structural properties of HBsAg and provide valuable insights into the mechanisms of immune escape in HBV, which may contribute to the development of more eÉective vaccines and therapeutic strategies. Keywords: Molecular Modeling, AlphaFold, S protein, M protein, Hepatitis B, vaccine