title: Electrochemical determination of thioredoxin redox states.
abstract: Thioredoxin (TRX) is a general protein disulfide reductase with a large number of biological functions, including its roles in human diseases. The TRX redox mechanism is based on reversible oxidation of two cysteine thiol groups to a disulfide, accompanied by the transfer of two protons. Using constant-current chronopotentiometric stripping analysis (CPSA) and the electrocatalytic TRX peak H, we have determined redox states of TRX at submicromolar TRX concentrations. A concentration of 1 nM TRX produces a well-developed peak H at moderate accumulation time without stirring. On the basis of this peak, interactions of 4-hydroxy-2-nonenal (HNE, product of lipid peroxidation) with TRX and the formation of TRX-HNE adducts were studied. CPSA of TRX at a carbon electrode is less sensitive and does not discriminate between reduced and oxidized forms of TRX.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-612 65 Brno, Czech Republic.
authors.forename: Vlastimil
authors.initials: V
authors.lastname: Dorcák
authors.forename: Emil
authors.initials: E
authors.lastname: Palecek
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000595:Amino Acid Sequence; D002244:Carbon / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D029968:Escherichia coli Proteins / Q000032:analysis / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D008628:Mercury / Q000737:chemistry; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D013879:Thioredoxins / Q000032:analysis / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D029968:Escherichia coli Proteins; C009139:pyrolytic carbon; D013879:Thioredoxins; D002244:Carbon; D006108:Graphite; D008628:Mercury; C027576:4-hydroxy-2-nonenal