FIGURE 5.

Autoinactivation of phospho-Thr²⁸⁶-αCaMKII in the presence of Ca²⁺. Temperature-dependent αCaMKII activity and time-dependent inactivation of Ca²⁺/CaM·phospho-Thr²⁸⁶-αCaMKII was monitored in the NADH-coupled assay. Activity of 50 nm enzyme in the presence of 50 μm syntide 2 as peptide substrate at 10 μm [Ca²⁺] concentration was measured at 22 (A), 30 (B), and 37 °C (C). Exponential decays of activity (traces 2 at 22 and 30 °C) were corrected for photobleaching (traces 1 at 22 and 30 °C) and were fitted with rate constants.