Denaturation can be caused by what factors?

• A. temperature
• B. pH
• C. salt concentration
• D. All of the above

Answer: (D)

Denaturation is the loss of a protein’s folded three‑dimensional structure due to disruption of the noncovalent interactions that keep it in shape, while the primary amino acid sequence stays the same. Temperature raises molecular motion and can break hydrogen bonds and weaken hydrophobic interactions in the protein core, causing it to unfold. Changes in pH shift the ionization states of amino acid side chains, breaking ionic bonds and salt bridges and disturbing hydrogen bonding networks, which also leads to unfolding. Salt concentration alters the solution’s ionic strength, damping electrostatic interactions that stabilize the folded state and can promote denaturation or precipitation at high levels. Since each factor can destabilize the folded conformation, all of these conditions can cause denaturation.