Question

What is the strongest type of interaction between two cysteine amino acids in a protein?

Answer 1

Disulfide:

1. Disulfide bonds are covalent bonds that are created between two sulfhydryl groups.
2. A reaction between two cysteine residues' sulfhydryl (SH) side chains results in the creation of disulfide bonds.
3. An ${\mathrm{S}}^{-}$ from one sulfhydryl group acts as a nucleophile, attacking the side chain of a second cysteine to create a disulfide bond, and in the process releases electrons for transfer.
4. Under oxidizing circumstances, disulfide bonds can develop and are crucial for the folding and stability of several proteins.
5. Disulfide bonds primary objective is to further stabilize the three-dimensional structure of protein molecules (during protein synthesis). Consequently, it is referred to as the tertiary protein structure's building component.
6. Additionally, it helps in the folding of individual polypeptide chains or inter proteins.

Therefore, the strongest type of interaction between two cysteine amino acids in a protein is disulfide bonds