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.