title: Histidine protonation and the activation of viral fusion proteins.
abstract: Many viral fusion proteins only become activated under mildly acidic condition (pH 4.5-6.5) close to the pK(a) of histidine side-chain protonation. Analysis of the sequences and structures of influenza HA (haemagglutinin) and flaviviral envelope glycoproteins has led to the identification of a number of histidine residues that are not only fully conserved themselves but have local environments that are also highly conserved [Kampmann, Mueller, Mark, Young and Kobe (2006) Structure 14, 1481-1487]. Here, we summarize studies aimed at determining the role, if any, that protonation of these potential switch histidine residues plays in the low-pH-dependent conformational changes associated with fusion activation of a flaviviral envelope protein. Specifically, we report on MD (Molecular Dynamics) simulations of the DEN2 (dengue virus type 2) envelope protein ectodomain sE (soluble E) performed under varied pH conditions designed to test the histidine switch hypothesis of Kampmann et al. (2006).
authors.affiliation: Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands. d.s.mueller@rug.nl
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Mueller
authors.forename: Thorsten
authors.initials: T
authors.lastname: Kampmann
authors.forename: Ragothaman
authors.initials: R
authors.lastname: Yennamalli
authors.forename: Paul R
authors.initials: PR
authors.lastname: Young
authors.forename: Bostjan
authors.initials: B
authors.lastname: Kobe
authors.forename: Alan E
authors.initials: AE
authors.lastname: Mark
mesh_terms: D003198:Computer Simulation; D018360:Crystallography, X-Ray; D018067:Flaviviridae / Q000737:chemistry; D006639:Histidine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D011522:Protons; D014760:Viral Fusion Proteins / Q000378:metabolism*
chemical_list: D011522:Protons; D014760:Viral Fusion Proteins; D006639:Histidine