Question

A tetrameric protein dissociates into dimers when the detergent sodium dodecyl sulfate (SDS) is added to a solution of the protein. But the dimers are termed SDS-resistant because they do not further dissociate into monomers in the presence of the detergent. What intermolecular forces might be acting at the dimer-dimer interface? Are the intermolecular forces acting at the monomer-monomer interface different? Explain.

Answer 1

Answer:

At the dimer-dimer interface there might be acting non-covalent forces (van der waals, Hidrogene bridges, hydrophobic forces)

At the monomer-monomer interface there might be covalent forces acting (disulfide bridges).

Explanation:

On the SDS-PAGE application  works by disrupting non-covalent bonds in the proteins, and so denaturing them. Therefore, the disulfide bridges won´t be disrupted, so the monomers will remain bounded.