Physicochemical Attributes of Hepatitis E Virus ORF4: A General Perspective

Hepatitis E virus (HEV) is the major viral pathogen causing hepatitis E infections worldwide. HEV is a member of the family Hepeviridae and genus Hepevirus. Although its indispensability in replication and pathogenesis of HEV has been demonstrated its physicochemical properties remain unexplored. Therefore, thorough investigation of the physicochemical parameters of open reading frame 4 (ORF4) proteins were carried out to examine the specific amnio acid composition patterns.

The properties considered for the analysis included amino acid composition, amino acid residues, aliphatic index, number of charged amino acid residues, instability index and grand average of hydropathy (GRAVY). The comparative analysis was conducted using computer analysis. The amino acid composition analysis suggested that the different host organisms exhibited varying amino acid percentages in ORF4 proteins. The results revealed that all the ORF4 proteins were highly endowed with amino acid residues such as Leu, Ser and Pro. Further, our analyses on instability, GRAVY and aliphatic indexes revealed that the ORF4 proteins were found to be unstable and hydrophobic in nature with high thermo stability value.

To the best of our knowledge, this study for the first time provides insights into the HEV ORF4 protein's physicochemical characteristics. Delineating the physicochemical characteristics of ORF4 protein will help in revealing its specific composition, which will further enhance our understanding towards the biology of HEV pathogenesis and infection.