Mastoparan binding induces a structural change affecting both the N-terminal and C-terminal domains of calmodulin: A 113Cd-NMR study

Abstract

113Cd-NMR studies of solutions of cadmium-loaded calmodulin (Cd 4CaM) and the tetradecapeptide mastoparan in different ratios show that mastoparan binds to Cd 4CaM 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 Cd 4CaM 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.