Altered calmodulin activity in buccal epithelial cells from cystic fibrosis patients

Boiled extracts of buccal epithelial cells from control subjects and cystic fibrosis patients were shown to possess calmodulin like activity, as assessed by their ability to activate calmodulin-deficient cyclic AMP phosphodiesterase. Estimation of calmodulin content, using pure calmodulin as standard revealed that control extracts contained 3.08 +/- 0.71 SEM (n = 7) micrograms calmodulin/mg protein and cystic fibrosis extracts 0.88 +/- 0.30 SEM (n = 12) micrograms calmodulin/mg protein (p less than 0.02 for difference from control). The results indicate that the biological activity of calmodulin is altered in buccal epithelial cells from cystic fibrosis individuals.