Role of Disulfide Bonds in Membrane Partitioning of a Viral Peptide

Sikdar, Samapan; Banerjee, Manidipa; Vemparala, Satyavani

The importance of disulfide bond in mediating viral peptide entry into host cells is well known. In the present work, we elucidate the role of disulfide (SS) bond in partitioning mechanism of membrane active Hepatitis A Virus-2B (HAV-2B) peptide, which harbours three cysteine residues promoting formation of multiple SS-bonded states. The inclusion of SS-bond not only results in a compact conformation but also induces distorted α-helical hairpin geometry in comparison to SS-free state, resulting in reduced hydrophobic exposure. Owing to this, the partitioning of HAV-2B peptide is completely or partly abolished. In a way, the disulfide bond regulates the partitioning of HAV-2B peptide, such that the membrane remodelling effects of this viral peptide are significantly reduced. The current findings may have potential implications in drug designing, targeting the HAV-2B protein by promoting disulfide bond formation within its membrane active region.