Table 1.

Differential effects of α₂δ and δ on the biophysical and binding properties of the α_1C currents

Properties	α1C	α1C/α2δ	α1C/δ
Peak current amplitude (pA)	−72  ± 15	−221  ± 24	−65  ± 11
Apparent activation threshold (mV)	≥−10	≥−20	≥−20
Potential for half-activation (mV)	19.6	8.7	8.5
Potential for half steady-state inactivation (mV)	−6.8	−15.9	−16.4
Decay of the current at 150 msec* (%)	19.5  ± 4.2	39.2  ± 9.8	36.4  ± 6.2
Rate of inactivation at +20 mV (μsec−1)	2.5  ± 0.5	4.3  ± 0.4	4.6  ± 0.7
Bmax (fmol/mg of protein)	67  ± 29	141  ± 39	41  ± 10
KD(nm)	0.9  ± 0.5	0.1  ± 0.04	2.4  ± 0.9

^* Currents were recorded during depolarizations from −80 to +30 mV.

B_max, Maximum binding capacity;K_D, dissociation constant (mean ± SE; n = 3–5).