title: Redox properties of the A-domain of the HMGB1 protein.
abstract: The High Mobility Group B1 (HMGB1) protein plays important roles in both intracellular (reductive) and extracellular (oxidative) environments. We have carried out quantitative investigations of the redox chemistry involving Cys22 and Cys44 of the HMGB1 A-domain, which form an intramolecular disulfide bond. Using NMR spectroscopy, we analyzed the real-time kinetics of the redox reactions for the A-domain in glutathione and thioredoxin systems, and also determined the standard redox potential. Thermodynamic experiments showed that the Cys22-Cys44 disulfide bond stabilizes the folded state of the protein. These data suggest that the oxidized HMGB1 may accumulate even in cells under oxidative stress.
authors.affiliation: Department of Biochemistry, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Blvd., 6.614D Basic Science Building, Galveston, TX 77555-0647, USA.
authors.forename: Debashish
authors.initials: D
authors.lastname: Sahu
authors.forename: Priyanka
authors.initials: P
authors.lastname: Debnath
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takayama
authors.forename: Junji
authors.initials: J
authors.lastname: Iwahara
mesh_terms: D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry*; D024243:HMGB1 Protein / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017434:Protein Structure, Tertiary; D013816:Thermodynamics; D013879:Thioredoxins / Q000737:chemistry / Q000378:metabolism
chemical_list: D024243:HMGB1 Protein; D013879:Thioredoxins; D003545:Cysteine