Abstract

To investigate the contribution to protein stability of electrostatic interactions between charged surface residues, we have studied the effect of substituting three negatively charged solvent exposed residues with their side-chain amide analogs in bovine calbindin D9k--a small (Mr 8,500) globular protein of the calmodulin superfamily. The free energy of urea-induced unfolding for the wild-type and seven mutant proteins has been measured. The mutant proteins have increased stability towards unfolding relative to the wild-type. The experimental results correlate reasonably well with theoretically calculated relative free energies of unfolding and show that electrostatic interactions between charges on the surface of a protein can have significant effects on protein stability. Study holds ProTherm entries: 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519 Extra Details: additive : EDTA(0.3 mM),ddG was measured in the presence of 5M urea urea induced unfolding; increased stability; calbindin D9k;,site-directed mutagenesis

Submission Details

ID: 9rAd7AFM

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:19 p.m.

Version: 1

Publication Details

Additional Information