Mastoparan binding induces a structural change affecting both the N‐terminal and C‐terminal domains of calmodulin

Abstract
113Cd‐NMR studies of solutions of cadmium‐loaded calmodulin (Cd4CaM) and the tetradecapeptide mastoparan in different ratios show that mastoparan binds to Cd4CaM with high affinity. The off‐rate of proteinbound mastoparan is found to be 40 s−1 or less. The binding of one molecule of mastoparan to Cd4CaM is observed to affect all four metal‐binding sites, indicating that both the N‐terminal and C‐terminal globular domains of the protein undergo conformational changes.