title: Crystal structure of the S-nitroso form of liganded human hemoglobin.
abstract: Although numerous reports have documented that the S-nitrosylation of cysteine residues by NO alters the activities of a wide variety of proteins, the direct visualization and the structural consequences of this reversible modification have not yet been reported for any protein. Here we describe the crystal structure of S-nitroso-nitrosylhemoglobin determined at a resolution of 1.8 A. The specific reaction of NO with Cys93beta is confirmed in this structure, and a large S-nitrosylation-induced change in the tertiary structure of the COOH-terminal dipeptides of the beta subunits provides additional insight into the stereochemical mechanism by which blood flow is regulated by the interaction of NO with hemoglobin.
authors.affiliation: Department of Biochemistry, College of Medicine, The University of Iowa, Iowa City 52242, USA.
authors.forename: N L
authors.initials: NL
authors.lastname: Chan
authors.forename: P H
authors.initials: PH
authors.lastname: Rogers
authors.forename: A
authors.initials: A
authors.lastname: Arnone
mesh_terms: D002263:Carboxyhemoglobin / Q000737:chemistry; D003198:Computer Simulation; D003460:Crystallization; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000031:analogs & derivatives / Q000737:chemistry; D006418:Heme / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D009569:Nitric Oxide / Q000737:chemistry; D009603:Nitroso Compounds / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D026403:S-Nitrosothiols; D013237:Stereoisomerism
chemical_list: D006454:Hemoglobins; D008024:Ligands; D009603:Nitroso Compounds; D026403:S-Nitrosothiols; D009569:Nitric Oxide; D006418:Heme; D002263:Carboxyhemoglobin; C021315:S-nitrosocysteine; D003545:Cysteine