Autocamtide-3 is a synthetic substrate specific for Ca2+/calmodulin-dependent protein kinase II. The sequence is based on the pseudosubstrate core located within the autoinhibitory domain of the enzyme. Autophosphorylation of Thr286 within the autoinhibitory domain traps bound calmodulin by greatly reducing its dissociation rate, thus prolonging the active state. Fluck, M. et al., J. Appl. Physiol., 88, 352, (2000); Yang, E.; Schulman, H., J. Biol. Chem., 274, 26199, (1999).