Question

What chemicals is used to reduce the complexity of 3D protein to interpret primary structure?

Answer 1

The chemicals used to reduce the complexity of 3D protein to interpret primary structure are:

a) β-mercaptoethanol or Dithiothreitol (DTT) which is a reducing agent and breaks the disulfide bonds.

(b) Urea or Guanidium chloride which is a denaturant and disrupts the non-covalent bonds.

Experiment proving the role of these chemicals: An experiment was planned by Christian Afinsen in 1960, where he used Ribonuclease A and treated it with Urea, a denaturant, and β-mercaptoethanol, a reducing agent. Ribonuclease gets denatured and disulfide bonds are broken. When proteins are allowed to renature by removing the denaturant and reductant, the protein regains its native conformation. This experiment helped in studying the amino acid sequence of a polypeptide chain and also interpreted that this polypeptide chain contains all the information required to fold chain into its native 3D structure.