Examining Protein Residue-Level Stability Using Theory and Experiment

As an extension of the theory of protein folding funnels, local frustration quantifies the optimality of these residue-level interactions relative to alternatives. Although this framework has existed for decades, experimental validation has remained elusive.

Past deep mutational scanning datasets enable experimental assessment across nearly 8,000 positions from 178 proteins. Results provide experimental evidence for theoretical predictions regarding the relationship between local frustration and protein sequence, structure, and evolution. An evaluation of three <i>in silico</i> methods shows modest agreement with benchmarks (r = 0.03 to 0.26), with the predominant local frustration predictor (Protein Frustratometer) capturing under 3% of the experimental variance.