What is the Difference Between DTT and Beta-Mercaptoethanol

The main difference between DTT and beta-mercaptoethanol is that DTT is a stronger reducing agent than beta-mercaptoethanol.

In chemistry, reducing agents are chemical compounds that give off or donate an electron to a compound in need of electrons, known as an electron recipient. A reducing agent may sometimes be called a reducer or a reductant, whereas the receiving species is called an oxidizing agent, oxidant, oxidizer, or electron acceptor. Before the reaction, these reducing agents have electrons, while the oxidizing agents lack electrons. This can be determined by their oxidation state. Hence, electrons are given out and received during the reaction by the species. The reducing power varies from species to species. DTT and beta-mercaptoethanol are two such effective reducing agents.

Key Areas Covered

1. What is DTT
     – Definition, Features
2. What is Beta-Mercaptoethanol
     – Definition, Features 
3. Similarity Between DTT and Beta-Mercaptoethanol
     – Outline of Common Features
4. Difference Between DTT and Beta-Mercaptoethanol
     – Comparison of Key Differences

Key Terms

BME, DTT, Beta-Mercaptoethanol, Thioglycol/ Mercaptoethanol/2-Mercaptoethanol

What is DTT

DTT is a redox reagent. DTT stands for dithiothreitol. This is a comparatively small molecule. However, DTT is a strong reducing reagent. The molecular formula of DTT is C₄H₁₀O₂S₂. Its oxidized form has a disulfide bond, and it is a six-membered ring. The racemic form of this reagent is commonly used. This is because both of its enantiomers are reactive. Its molecular weight is 154.3. Moreover, its boiling point is 115 degrees Celsius. DTT helps to break down protein disulfide bonds. It also stabilizes enzymes and other proteins.

DTT is involved in reactions where disulfide exchange happens. It is used at 1-10 mM for protein SS reduction. It can even cross biological membranes. Moreover, the reduction of a disulfide bond follows two thiol-disulfide exchange reactions. Here, the oxidation of DTT happens, creating a reduced disulfide bond.

The redox potential of DTT at pH 7 is -0.33. The reducing power of DTT is seen only above the pH values greater than 7. This is because only the thiolate form with the negative charge is reactive. Furthermore, DTT’s ability to act as a reducing agent decreases with the decrease in the pH levels.

DTT is also used as an antioxidant. Against ionization radiation in living cells, DTT works as a protective agent. DTT also accelerates the decomposition of sodium nitroprusside. It also has uses in the study of disulfide exchange reactions. This is to reconstruct the proteins before the electrophoresis analysis by reducing the disulfide bonds of the proteins. DTT becomes useful in increasing the efficiency of ethanol production by using biofuels. It also acts as an oxidizing agent to prevent the population of mixed-disulfide species.

What is Beta-Mercaptoethanol

Beta-mercaptoethanol is a highly volatile material. The chemical formula of the compound is HSCH₂CH₂OH. The molecular weight of the compound is 78.14. Other names for beta-mercaptoethanol include thioglycol/ mercaptoethanol/2-mercaptoethanol or BME. It has the appearance of a water-white liquid. This compound has a characteristic odor that is very unpleasant. The boiling point is 158 degrees of Celcius, while its melting point is less than 25 degrees of Celsius. It is miscible in water.

This chemical is useful in making rubber chemicals, flotation agents, insecticides, and plasticizers, to make dyestuff. It is also a PVC stabilizer, solvent, and textile auxiliary. In addition, it is helpful in organic synthesis, mainly as a biochemical research tool.

BME denatures some proteins. Furthermore, breaking the S-S bond alters the tertiary and quaternary structures of some proteins. This ability to disrupt the structure of proteins makes this chemical compound useful in the analysis of proteins.

Similarity Between DTT and Beta-Mercaptoethanol

• Both DTT and beta-mercaptoethanol are effective reducing agents that help in breaking disulfide bonds.

Difference Between DTT and Beta-Mercaptoethanol

Definition

DTT (dithiothreitol) is a strong redox reagent, while beta-mercaptoethanol is a highly volatile material.

Strength

DTT is a stronger reducing agent than beta-mercaptoethanol.

Stability

The stability of DTT is low, while the stability of beta-mercaptoethanol is comparatively higher.

Odor

DTT is odorless, whereas beta mercaptoethanol has a very strong and unpleasant odor.

Conclusion

Reducing agents are chemical compounds that give off or donate an electron to a compound. DTT and beta-mercaptoethanol are two good reducing agents. The main difference between DTT and beta-mercaptoethanol is that DTT is a stronger reducing agent than beta-mercaptoethanol.

Reference:

1. “Dithiothreitol.” PubChem. National Library of Medicine.
2. “Beta-Mercaptoethanol.” PubChem. National Library of Medicine.

Image Courtesy:

1. “Dithiothreitol-3D-balls” By Jynto (talk) – This image was created with Discovery Studio Visualizer. (CC0) via Commons Wikimedia
2. “2-mercaptoethanol-3D-balls” By Benjah-bmm27 and Jynto – Derivative of public domain file from Commons., (Public Domain) via Commons Wikimedia