Rate constants for entry (A) and exit (B) of Ca, from microscopic and macroscopic data

“Single-channel” rates are reciprocals of closed times (B), or the reciprocal of the open time minus the reciprocal of the open time in 0.1 μM Ca (A), = 3–4. “Frequency domain” time constants are from the fast corner frequency as in , and the steady-state block (p) was estimated from the steady-state currents in 10 μM Ca, divided by the steady-state current in 0.1 μM Ca (assumed to be zero block), = 3. “Time domain” rates were calculated from time constants () and steady-state block (from ); = 9 for 10 μM Ca and = 3 for 3 μM Ca. For macroscopic data (frequency domain and time domain), rate constants were calculated assuming 1/τ = k + k, and p = k/(k + k); thus k = p/τ, k = 1/τ − k. In A, bimolecular rate constants were calculated by dividing k by the free Ca. The same symbols were used in A and B.<p><b>Copyright information:</b></p><p>Taken from "Permeation and Gating in Ca3.1 (α1G) T-type Calcium Channels Effects of Ca, Ba, Mg, and Na"</p><p></p><p>The Journal of General Physiology 2008;132(2):223-238.</p><p>Published online Jan 2008</p><p>PMCID:PMC2483336.</p><p>