Which reducing agent is known for breaking disulfide bonds in proteins?

The reducing agent that is well-known for breaking disulfide bonds in proteins is β-mercaptoethanol. Disulfide bonds are covalent linkages that often contribute to the stability and structure of protein molecules by linking the thiol groups of cysteine residues. When proteins are denatured or when their structure needs to be reduced, β-mercaptoethanol plays a crucial role due to its ability to donate electrons and reduce disulfide bonds, converting them back to free thiol groups.

This reduction process is essential in many biochemical applications, such as protein analysis, where maintaining a reduced state is necessary for accurately determining molecular weights or conducting certain types of electrophoresis. The ability of β-mercaptoethanol to effectively break disulfide bonds is a property that makes it invaluable in protein biochemistry and molecular biology techniques.

Other options do not serve as reducing agents for disulfide bonds: Tris buffer is primarily a buffering agent, glycerol acts as a cryoprotectant or stabilizer in biochemical assays, and while DTT (dithiothreitol) also reduces disulfide bonds, it is not the choice indicated in this context. Therefore, β-mercaptoethanol