title: Hydrogen peroxide and hypochlorous acid influx through the major S. Typhimurium porin OmpD is affected by substitution of key residues of the channel.
abstract: OmpD is the major Salmonella enterica serovar Typhimurium (S. Typhimurium) porin and mediates hydrogen peroxide (H2O2) influx. The results described herein extend this finding to hypochlorous acid (HOCl), another reactive oxygen species that is also part of the oxidative burst generated by the phagosome. S. Typhimurium cells lacking OmpD show decreased HOCl influx, and OmpD-reconstituted proteoliposomes show an increase in the uptake of the toxic compound. To understand this physiologically relevant process, we investigated the role of key OmpD residues in H2O2 and NaOCl transport. Using a theoretical approach, residue K16 was defined as a major contributor to the channel electrostatic properties, and E111 was shown to directly participate in the size-exclusion limit of the channel. Together, we provide theoretical, genetic, and biochemical evidence that OmpD mediates H2O2 and NaOCl uptake, and that key residues of the channel are implicated in this process.
authors.affiliation: Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile; Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103, Chile.
authors.forename: Daniel
authors.initials: D
authors.lastname: Aguayo
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Pacheco
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Chile.
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Morales
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Collao
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Roberto
authors.initials: R
authors.lastname: Luraschi
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Carolina
authors.initials: C
authors.lastname: Cabezas
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Paulina
authors.initials: P
authors.lastname: Calderón
authors.affiliation: Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile; Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: González-Nilo
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Gil
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Iván L
authors.initials: IL
authors.lastname: Calderón
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: csaavedra@unab.cl.
authors.forename: Claudia P
authors.initials: CP
authors.lastname: Saavedra
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006997:Hypochlorous Acid / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D018272:Porins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: C470933:OmpD protein, Salmonella typhimurium; D018272:Porins; D006997:Hypochlorous Acid; D006861:Hydrogen Peroxide
keywords: Homology modeling; Hydrogen peroxide; Hypochlorous acid; Molecular simulations; OmpD porin