Dithiothreitol

Dithiothreitol

Names
Preferred IUPAC name (2S,3S)-1,4-Bis(sulfanyl)butane-2,3-diol
Other names (2S,3S)-1,4-Dimercaptobutane-2,3-diol (no longer recommended) D-threo-1,4-Dimercaptobutane-2,3-diol D-threo-1,4-Dimercapto-2,3-butanediol 1,4-Dithio-D-threitol Cleland's reagent Reductacryl
Identifiers
CAS Number	3483-12-3 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:42170 Y
ChEMBL	ChEMBL406270 N
ChemSpider	393541 Y
DrugBank	DB04447 Y
ECHA InfoCard	100.020.427
PubChem	446094
UNII	T8ID5YZU6Y Y
InChI InChI=1S/C4H10O2S2/c5-3(1-7)4(6)2-8/h3-8H,1-2H2/t3-,4-/m1/s1 Y Key: VHJLVAABSRFDPM-QWWZWVQMSA-N Y InChI=1/C4H10O2S2/c5-3(1-7)4(6)2-8/h3-8H,1-2H2/t3-,4-/m1/s1 Key: VHJLVAABSRFDPM-QWWZWVQMBU
SMILES C([C@H]([C@@H](CS)O)O)S
Properties
Chemical formula	C4H10O2S2
Molar mass	154.253 g/mol
Appearance	White solid
Melting point	42 to 43 °C (108 to 109 °F; 315 to 316 K)
Boiling point	125 to 130 °C (257 to 266 °F; 398 to 403 K) at 2 mmHg
Solubility in water	Soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Dithiothreitol (DTT) is the common name for a small-molecule redox reagent also known as Cleland's reagent. DTT's formula is C₄H₁₀O₂S₂ and the chemical structure of one of its enantiomers in its reduced form is shown on the right; its oxidized form is a disulfide bonded 6-membered ring (shown below). The reagent is commonly used in its racemic form, as both enantiomers are reactive. Its name derives from the four-carbon sugar, threose. DTT has an epimeric ('sister') compound, dithioerythritol (DTE).

DTT is a reducing agent; once oxidized, it forms a stable six-membered ring with an internal disulfide bond. It has a redox potential of -0.33 V at pH 7. The reduction of a typical disulfide bond proceeds by two sequential thiol-disulfide exchange reactions and is illustrated below. The reduction usually does not stop at the mixed-disulfide species because the second thiol of DTT has a high propensity to close the ring, forming oxidized DTT and leaving behind a reduced disulfide bond. The reducing power of DTT is limited to pH values above 7, since only the negatively charged thiolate form -S⁻ is reactive (the protonated thiol form -SH is not); the pKa of the thiol groups is 9.2 and 10.1.

DTT is used as a reducing or "deprotecting" agent for thiolated DNA. The terminal sulfur atoms of thiolated DNA have a tendency to form dimers in solution, especially in the presence of oxygen. Dimerization greatly lowers the efficiency of subsequent coupling reactions such as DNA immobilization on gold in biosensors. Typically DTT is mixed with a DNA solution and allowed to react, and then is removed by filtration (for the solid catalyst) or by chromatography (for the liquid form). The DTT removal procedure is often called "desalting." Generally, DTT is used as a protecting agent that prevents oxidation of thiol groups.