Thermodynamic Effects of Disulfide Bonds on the Structural Stability of Proteins

Abstract

Disulfide bond has been believed to stabilize the proteins structure by restricting a freedom of the unfolded chain. To examine if this notion is true or not, I prepared the trypsin inhibitor and immunoglobulin fold domain mutants lacking or introducing the disulfide bonds. Thermodynamic analysis of these mutants indicates that the effects of disulfide bond on the stability of protein structure include conformational entropy of the native state and intramolecular interaction, in addition to the restriction of the unfolded chain.