A potent, versatile disulfide-reducing agent from aspartic acid

J Am Chem Soc. 2012 Mar 7;134(9):4057-9. doi: 10.1021/ja211931f. Epub 2012 Feb 21.


Dithiothreitol (DTT) is the standard reagent for reducing disulfide bonds between and within biological molecules. At neutral pH, however, >99% of DTT thiol groups are protonated and thus unreactive. Herein, we report on (2S)-2-amino-1,4-dimercaptobutane (dithiobutylamine or DTBA), a dithiol that can be synthesized from l-aspartic acid in a few high-yielding steps that are amenable to a large-scale process. DTBA has thiol pK(a) values that are ~1 unit lower than those of DTT and forms a disulfide with a similar E°' value. DTBA reduces disulfide bonds in both small molecules and proteins faster than does DTT. The amino group of DTBA enables its isolation by cation-exchange and facilitates its conjugation. These attributes indicate that DTBA is a superior reagent for reducing disulfide bonds in aqueous solution.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspartic Acid / chemistry*
  • Aspartic Acid / metabolism
  • Creatine Kinase / chemistry
  • Creatine Kinase / metabolism
  • Disulfides / chemistry*
  • Disulfides / metabolism
  • Dithiothreitol / chemistry*
  • Dithiothreitol / metabolism
  • Molecular Structure
  • Oxidation-Reduction
  • Papain / chemistry
  • Papain / metabolism
  • Stereoisomerism


  • Disulfides
  • Aspartic Acid
  • Creatine Kinase
  • Papain
  • Dithiothreitol