West Nile virus is neutralized by HOCl-modified human serum albumin that binds to domain III of the viral envelope protein E.

The outbreaks of West Nile virus (WNV), an emerging flavivirus recently implicated in outbreaks of fatal encephalitis, necessitate the development of effective anti-WNV drugs. In this study, it is demonstrated that human serum albumin is transformed into a WNV antiviral substance by hypochlorite (HOCl) modification. The HOCl-modified albumin efficiently neutralized WNV in vitro (EC50=300 nM) and showed binding to a recombinant protein, representing the domain III of the WNV external envelope E glycoprotein.