Protein Denaturation

A protein can only carry out its biological activity in its native conformation under optimal conditions.

Exposure to certain chemicals or heavy metals, or changes in pH or temperature can denature the protein, that is, disrupt its three-dimensional structure and make it biologically inactive.

During denaturation, the covalent and non-covalent interactions holding together the protein's tertiary and secondary structures break, leading to the uncoiling of helices, the destabilization of beta sheets, or even the complete unfolding of the protein into its primary polypeptide chain.

In some cases, when the optimal conditions are re-established, the denatured protein can refold into its functional form through a process called renaturation.

For instance, when the blood pH falls below 7.35, excess H⁺ ions bind to hemoglobin, inducing conformational changes in its structure. These structural changes prevent hemoglobin from binding and transporting oxygen.

However, when the normal blood pH is restored, hemoglobin releases the attached H⁺ ions, reacquires its biologically active form, and resumes oxygen transport.