title: Membrane anchoring stabilizes and favors secretion of New Delhi metallo-β-lactamase.
abstract: Carbapenems, 'last-resort' β-lactam antibiotics, are inactivated by zinc-dependent metallo-β-lactamases (MBLs). The host innate immune response withholds nutrient metal ions from microbial pathogens by releasing metal-chelating proteins such as calprotectin. We show that metal sequestration is detrimental for the accumulation of MBLs in the bacterial periplasm, because those enzymes are readily degraded in their nonmetallated form. However, the New Delhi metallo-β-lactamase (NDM-1) can persist under conditions of metal depletion. NDM-1 is a lipidated protein that anchors to the outer membrane of Gram-negative bacteria. Membrane anchoring contributes to the unusual stability of NDM-1 and favors secretion of this enzyme in outer-membrane vesicles (OMVs). OMVs containing NDM-1 can protect nearby populations of bacteria from otherwise lethal antibiotic levels, and OMVs from clinical pathogens expressing NDM-1 can carry this MBL and the blaNDM gene. We show that protein export into OMVs can be targeted, providing possibilities of new antibacterial therapeutic strategies.
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.|Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Lisandro J
authors.initials: LJ
authors.lastname: González
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.|Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Bahr
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Toshiki G
authors.initials: TG
authors.lastname: Nakashige
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Nolan
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA.|Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.|Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA.|Department of Microbiology and Molecular Biology, Case Western Reserve University, Cleveland, Ohio, USA.|Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bonomo
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.|Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Vila
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D006090:Gram-Negative Bacteria / Q000378:metabolism*; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1