Table 1.
Reversible inhibition of [3H]InsP3 binding by calmodulin
Calmodulin, μM | Inhibition of [3H]InsP3 binding, % |
---|---|
3 | 54 ± 1 |
10 | 72 ± 2 |
10 then 3 | 49 ± 1 |
SPA methods were used to compare [3H]InsP3 binding to receptors incubated with 3 or 10 μM calmodulin for 40 min. In parallel, receptors were incubated with 10 μM calmodulin (20 min) and then incubated for a further 20 min after dilution to reduce the calmodulin concentration to 3 μM without otherwise changing the composition of the medium. The results (means ± SEM, n = 6) are expressed relative to the specific [3H]InsP3 binding detected in parallel incubations without calmodulin.