title: A potent, versatile disulfide-reducing agent from aspartic acid.
abstract: 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.
authors.affiliation: Department of Chemistry, ‡University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Lukesh
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Palte
authors.forename: Ronald T
authors.initials: RT
authors.lastname: Raines
mesh_terms: D001224:Aspartic Acid / Q000737:chemistry* / Q000378:metabolism; D003402:Creatine Kinase / Q000737:chemistry / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry* / Q000378:metabolism; D004229:Dithiothreitol / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010206:Papain / Q000737:chemistry / Q000378:metabolism; D013237:Stereoisomerism
chemical_list: D004220:Disulfides; D001224:Aspartic Acid; D003402:Creatine Kinase; D010206:Papain; D004229:Dithiothreitol