DL-1,4-Dithiothreitol
[CAS# 3483-12-3]

Identification

• Classification: Biochemical >> Carbohydrate >> Monosaccharide
• Name: DL-1,4-Dithiothreitol
• Synonyms: Dithiothreitol; threo-1,4-Dimercapto-2,3-butanediol; Cleland's reagent; DTT
• Molecular Formula: C₄H₁₀O₂S₂
• Molecular Weight: 154.25
• CAS Registry Number: 3483-12-3
• EC Number: 222-468-7
• SMILES: C([C@H]([C@@H](CS)O)O)S

Properties

• Melting point: 38-43 °C
• Boiling point: 125-130 °C (2 mmHg)
• Water solubility: freely soluble

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H302-H315-H318-H319-H412
• Safety Statements: P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin sensitization	Skin Sens.	1A	H317
Eye irritation	Eye Irrit.	2A	H319
Germ cell mutagenicity	Muta.	2	H341
Specific target organ toxicity - single exposure	STOT SE	3	H336
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312

Discovery and Applications

DL-1,4-dithiothreitol (DTT) is a small molecule reducing agent with the chemical formula C4H10O2S2. It was discovered by Cleland in the early 1960s while he was searching for a compound that could reduce disulfide bonds in proteins and protect thiol groups from oxidation. The unique properties of this compound make it a valuable tool in biochemical and molecular biological research.

DTT is a white crystalline powder that is soluble in water and is usually used in its racemic form, DL-1,4-dithiothreitol. Its structure has two thiol groups (-SH) that are ready to donate electrons to reduce disulfide bonds (S-S) in proteins and peptides, converting them to free thiols. This reduction is essential for studying protein structure and function and for a variety of biochemical applications.

The reducing action of DTT involves a thiol-disulfide exchange reaction, in which the thiol group in DTT donates electrons to a disulfide bond, splitting it into two free thiol groups. This reduction is facilitated by the formation of stable intramolecular disulfide bonds within the DTT molecule itself, which drives the reaction to completion.

DTT is widely used to break disulfide bonds in proteins and peptides. This reduction is essential for denaturing proteins, allowing for more accurate analysis of their structure and function. It is a standard reagent in SDS-PAGE, ensuring that proteins are completely denatured and separated according to their molecular weight.

DTT is used to protect thiol groups in enzymes and other proteins from oxidation during purification and storage. This protection helps maintain enzyme activity and stability, making DTT a key ingredient in enzyme assays and other biochemical experiments.

In molecular biology, DTT is used in the preparation of RNA samples to prevent the formation of secondary structures that could interfere with reverse transcription and other downstream applications. It ensures that the RNA remains in a linear single-stranded form.

DTT is used for the reductive cleavage of disulfide bonds in organic compounds in chemical synthesis. Its ability to selectively reduce these bonds without affecting other functional groups makes it a versatile reagent in synthetic chemistry.

DTT should be handled with care as it is irritating to the skin, eyes, and respiratory tract. It should be used in a well-ventilated area with appropriate personal protective equipment. DTT solution should be freshly prepared and protected from air and light to prevent oxidation and maintain its reducing power.

References

2023. Applications of Dithiothreitol in Biochemistry. Biochemical Journal, 480(9).
DOI: 10.1042/BCJ202300123