title: Quantification of thiols and disulfides.
abstract: BACKGROUND
  Disulfide bond formation is a key posttranslational modification, with implications for structure, function and stability of numerous proteins. While disulfide bond formation is a necessary and essential process for many proteins, it is deleterious and disruptive for others. Cells go to great lengths to regulate thiol-disulfide bond homeostasis, typically with several, apparently redundant, systems working in parallel. Dissecting the extent of oxidation and reduction of disulfides is an ongoing challenge due, in part, to the facility of thiol/disulfide exchange reactions.
  
  
  METHODS
  In the present account, we briefly survey the toolbox available to the experimentalist for the chemical determination of thiols and disulfides. We have chosen to focus on the key chemical aspects of current methodology, together with identifying potential difficulties inherent in their experimental implementation.
  
  
  CONCLUSIONS
  While many reagents have been described for the measurement and manipulation of the redox status of thiols and disulfides, a number of these methods remain underutilized. The ability to effectively quantify changes in redox conditions in living cells presents a continuing challenge.
  
  
  CONCLUSIONS
  Many unresolved questions in the metabolic interconversion of thiols and disulfides remain. For example, while pool sizes of redox pairs and their intracellular distribution are being uncovered, very little is known about the flux in thiol-disulfide exchange pathways. New tools are needed to address this important aspect of cellular metabolism. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.
authors.affiliation: Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen Biocenter, DK-2200 Copenhagen, Denmark. Electronic address: jrwinther@bio.ku.dk.
authors.forename: Jakob R
authors.initials: JR
authors.lastname: Winther
authors.forename: Colin
authors.initials: C
authors.lastname: Thorpe
mesh_terms: D000818:Animals; D004220:Disulfides / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D010084:Oxidation-Reduction; D011506:Proteins / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000032:analysis* / Q000737:chemistry
chemical_list: D004220:Disulfides; D011506:Proteins; D013438:Sulfhydryl Compounds
keywords: 1-cyano-4-dimethylamino-pyridinium; 2-mercato ethanol; 4,4′-dithiodipyridine; 4-(aminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole; 4-DPS; 4-acetamido-4′-maleimidylstilbene-2,2′-disulfonic acid; 5,5′-dithiobis-(2-nitrobenzoic) acid; 5-thio-2-nitrobenzoic acid; 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate; ABD-F; AMS; CDAP; DTNB; Detection; EDTA; ER; Exchange; GSH; GSSG; HMD; MBBr; ME; MMTS; Modification; Monobromobimane; Nucleophile; PAGE; PEG; Redox; S-methyl methanethiosulfonate; SBD-F; SDS; TCEP; THP; TNB; endoplasmic reticulum; ethylenediamine tetraacetic acid; glutathione; glutathione disulfide; heavy maleimide derivative; polyacrylamide gel electrophoresis; polyethyleneglycol; sodium dodecylsulfate; tris(2-carboxyethyl) phosphine; tris(2-hydroxyethyl) phosphine