... with Ca2+calmodulin, they should also inhibit the activity of calcineurin. The four model peptides lesueurin, citropin 1.1,frenatin 3 and caerin 1. 9, all inhibit the activity of calcineu-rin, but at ... the presence of increasing concentrations of Ca2+calmodulin, the inhibition dropped by 50% in each case. In addition,these peptides also inhibit the activity of calcineurin, anotherenzyme that ... to inhibit nNOS by displacingCa2+calmodulin from the calmodulin b inding domain of nNOS. In this p rocedure, the nNOS inhibition experimentswere carried out with citropin 1.1, frenatin 3, and...