title: Five-coordinate H64Q neuroglobin as a ligand-trap antidote for carbon monoxide poisoning.
abstract: Carbon monoxide (CO) is a leading cause of poisoning deaths worldwide, with no available antidotal therapy. We introduce a potential treatment paradigm for CO poisoning, based on near-irreversible binding of CO by an engineered human neuroglobin (Ngb). Ngb is a six-coordinate hemoprotein, with the heme iron coordinated by two histidine residues. We mutated the distal histidine to glutamine (H64Q) and substituted three surface cysteines with less reactive amino acids to form a five-coordinate heme protein (Ngb-H64Q-CCC). This molecule exhibited an unusually high affinity for gaseous ligands, with a P50(partial pressure of O2at which hemoglobin is half-saturated) value for oxygen of 0.015 mmHg. Ngb-H64Q-CCC bound CO about 500 times more strongly than did hemoglobin. Incubation of Ngb-H64Q-CCC with 100% CO-saturated hemoglobin, either cell-free or encapsulated in human red blood cells, reduced the half-life of carboxyhemoglobin to 0.11 and 0.41 min, respectively, from ≥200 min when the hemoglobin or red blood cells were exposed only to air. Infusion of Ngb-H64Q-CCC to CO-poisoned mice enhanced CO removal from red blood cells, restored heart rate and blood pressure, increased survival, and was followed by rapid renal elimination of CO-bound Ngb-H64Q-CCC. Heme-based scavenger molecules with very high CO binding affinity, such as our mutant five-coordinate Ngb, are potential antidotes for CO poisoning by virtue of their ability to bind and eliminate CO.
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Ivan
authors.initials: I
authors.lastname: Azarov
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Rose
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Qinzi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Xueyin N
authors.initials: XN
authors.lastname: Huang
authors.affiliation: Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Belanger
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Lanping
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Kamil B
authors.initials: KB
authors.lastname: Ucer
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Charles F
authors.initials: CF
authors.lastname: McTiernan
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: O'Donnell
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Sruti
authors.initials: S
authors.lastname: Shiva
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Jesús
authors.initials: J
authors.lastname: Tejero
authors.affiliation: Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.|Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Kim-Shapiro
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA. gladwinmt@upmc.edu.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Gladwin
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001921:Brain / Q000378:metabolism; D002248:Carbon Monoxide / Q000737:chemistry; D002249:Carbon Monoxide Poisoning / Q000175:diagnosis*; D002263:Carboxyhemoglobin / Q000235:genetics; D004912:Erythrocytes / Q000378:metabolism*; D005740:Gases; D005818:Genetic Engineering / Q000379:methods; D005914:Globins / Q000235:genetics* / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D007700:Kinetics; D008024:Ligands; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000502:physiology*; D000078787:Neuroglobin; D010100:Oxygen / Q000737:chemistry; D011312:Pressure; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D005740:Gases; D008024:Ligands; D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D011994:Recombinant Proteins; D002248:Carbon Monoxide; D005914:Globins; D002263:Carboxyhemoglobin; D010100:Oxygen