TABLE 1

IC50 values of AOSK1 peptides on various K+ channel subtypes For each peptide, the IC50 value is provided in nanomolar concentration. Data for OSK1 are shown for comparison. No effects of the peptides were observed for Kv1.4, Kv1.5, Kv1.6, Kv1.7, Kv3.1, Kv11.1, KCa1.1, and KCa2.1 at micromolar concentrations. Specificity factors (the ratios between IC50 values for two channels) are shown for the sake of comparison.

OSK1 AOSK1 [Δ1]-AOSK1 [Δ1,Thr2]-AOSK1 [Δ1–4]-AOSK1 [Δ1–6]-AOSK1 [Δ1–7]-AOSK1 [Δ36–38]-AOSK1
LD50 (μg/kg) 2 2.5 3 3 5 6.5 15 40
IC50 (nM)
   Kv1.1 0.60 ± 0.04 0.40 ± 0.01 0.19 ± 0.01 0.36 ± 0.04 2.67 ± 0.50 2.18 ± 0.30 7.90 ± 1.20 365 ± 65
   Kv1.2 5.40 ± 1.89 2.96 ± 0.01 30 ± 7 100 ± 5 245 ± 77 634 ± 5 N.E. N.E.
   Kv1.3 0.014 ± 0.001 0.003 ± 0.001 0.025 ± 0.002 0.021 ± 0.004 0.038 ± 0.001 0.045 ± 0.002 0.114 ± 0.005 1.85 ± 0.70
   Kv3.2 N.E. 1000 ± 100 95 ± 10 65 ± 10 N.E. N.E. N.E. N.E.
   KCa3.1 225 ± 10 228 ± 92 425 ± 25 N.E. N.E. N.E. N.E. N.E.
Specificity factor
   Kv1.3 vs. Kv1.1 43 133 8 17 70 48 69 197
   Kv1.3 vs. Kv1.2 386 987 1200 4762 6447 14089 N.D. N.D.
   Kv1.1 vs. Kv1.2 9 7 158 2778 92 291 N.D. N.D.

  • N.E., no effects; N.D., not determined.