Figure 3. Ability of various CaM mutants to activate eNOS enzymes.

A: Citrulline formation activity. B: Cytochrome c reduction activity. Both citrulline formation and cytochrome c reduction were measured in the presence of saturating concentration of each CaM construct (0.5 μM). NOS activities were expressed as percentage of the respective maximal NOS activity (100%) which was obtained with the eNOS bound to wild-type CaM. Under these conditions, the activities for eNOS bound to wild-type CaM were ∼14 min⁻¹ for citrulline formation, and ∼286 min⁻¹ for cytochrome c reduction. Data are presented as means±standard deviation. * denotes p<0.05, ** <0.01, NS, not significant difference as compared to wild-type CaM. Each experiment was performed in triplicate and repeated three times.