Staphylococcalnuclease is a single domain protein with 149 amino acids. It has no disulfide bonds, which makes it a simple model for the study of pro-tein folding. In this study, 20 mutants of this protein were generated each with a single base substitution of glycine for negatively charged glutamic acid or aspartic acid. Using differential scanning microcalorimetry in ther-mal denaturation experiments, we identified two mutants, E75G and E129G, having approximately 43% and 44%, respectively, lowerDHcal values than the wild-type protein
