title: Porphyrin π-stacking in a heme protein scaffold tunes gas ligand affinity.
abstract: The role of π-stacking in controlling redox and ligand binding properties of porphyrins has been of interest for many years. The recent discovery of H-NOX domains has provided a model system to investigate the role of porphyrin π-stacking within a heme protein scaffold. Removal of a phenylalanine-porphyrin π-stack dramatically increased O2, NO, and CO affinities and caused changes in redox potential (~40mV) without any structural changes. These results suggest that small changes in redox potential affect ligand affinity and that π-stacking may provide a novel route to engineer heme protein properties for new functions.
authors.affiliation: Department of Chemistry, Emory University, Atlanta, GA 30322, United States.
authors.forename: Emily E
authors.initials: EE
authors.lastname: Weinert
authors.forename: Christine M
authors.initials: CM
authors.lastname: Phillips-Piro
authors.forename: Michael A
authors.initials: MA
authors.lastname: Marletta
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry* / Q000378:metabolism; D002248:Carbon Monoxide / Q000737:chemistry* / Q000378:metabolism; D006420:Hemeproteins / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D011166:Porphyrins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D006420:Hemeproteins; D008024:Ligands; D011166:Porphyrins; D002245:Carbon Dioxide; D002248:Carbon Monoxide; D010100:Oxygen
keywords: Bioinorganic chemistry; H-NOX; Heme proteins; Pi interactions; Porphyrins; Redox chemistry