Hydrophobic peptides affect binding of calmodulin and Ca2+ as explored by H/D amide exchange and mass spectrometry

▶ Capabilities of MS-based PLIMSTEX illustrated for calmodulin-peptide binding. ▶ Digestion of calmodulin following HDX reveals binding at component peptide level. ▶ The presence of peptide ligands increases Ca2+ binding affinity to calmodulin. ▶ Similar HDX patterns for binding of three peptides suggest common structures.