In this work, we use the GFN2-xTB semi-empirical tight-binding method to simultaneously and rapidly capture the dynamics of both nuclei and their electrons in small model peptides that differ by only a few residues in their primary sequence. We specifically investigate the extent to which charge coupling can explain differences in stability for variants of Trp-cage that differ by a small number of N-terminal substitutions[117, 118] (Figure ). TC10b was designed to have greater helical propensity than TC5b, increasing the stability of the Nterminal a-helix . We focus on Trp-cage because its folding and unfolding has been widely studied . Furthermore Trp-cage's ca. 300 atom size makes it possible to carry out relatively long-time dynamics (i.e., 800 ps in total). Our analysis reveals a shift in the network of charge-coupled residues when an N-terminal Asn is replaced with a nearly isostructural Asp residue. This observation suggests that charge coupling analysis provides complementary insight into protein structure-function relationships alongside more established geometric coupling measures. We confirm that trends observed in the electronic structure of the semi-empirical models hold when snapshots are carried out using full DFT modeling with a range-separated hybrid functional, potentially guiding lower-cost strategies for obtaining charge coupling data.