High pKa variability of cysteine residues in structural databases and the effect of H-bond contributions

Objective: Our first objective was to extensively compare two most common empirical protein pKa predictors, propka1.0 (ppka1) and propka3.0 (ppka3); we have specifically compared them as tools for high-throughput analyses of structural datasets with a particular focus on the amino acid Cysteine (Cys); afterwards, our goal was to assess their performances with known instances of reactive Cys residues.