Metal ions and protons compete for ligand atoms in disordered peptides: Examples from computer simulations of copper binding to the prion tandem repeat

► Proteins involved in neurodegenerative diseases display different structures and charges. ► These ligands can attract metal ions while sampling binding prone configurations. ► Attracted metal ions activate peptide groups for proton exchange with water. ► Models that include explicit water and breakable bonds are, therefore, essential.