Table 2. Kinetic Data for Monovalent and Bivalent Ligands at hNa_V1.4 and hNa_V1.7 Determined via Patch-Clamp Electrophysiology.

	Ligand	kon*a (s–1)	kon (nM–1 s–1)	koff (s–1)	Kd (nM)
hNaV1.4
1	[m3-HwTx-IV]-[PEG80]-[K-KIIIA]	(1.48 ± 0.04) × 10–2	nd	irreversibleb	nd
2	[m3-HwTx-IV]-[PEG60]-[K-KIIIA]	(1.52 ± 0.12) × 10–2	nd	irreversibleb	nd
6	AzK-KIIIA	(1.39 ± 0.15) × 10–2	3.97 × 10–5	(1.18 ± 0.18) × 10–3	2.97 × 10
9	S-m3-HwTx-IV	(6.25 ± 1.02) × 10–3	1.02 × 10–6	(4.11 ± 0.36) × 10–3	4.03 × 103
8	[K-KIIIA]-[PEG80]	(9.75 ± 0.89) × 10–3	nd	nd	nd
12	[m3-HwTx-IV]-[PEG80]	(9.19 ± 0.79) × 10–3	nd	nd	nd
hNaV1.7
1	[m3-HwTx-IV]-[PEG80]-[K-KIIIA]	(4.28 ± 0.48) × 10–3	nd	irreversibleb	nd
6	AzK-KIIIA	(1.60 ± 0.03) × 10–2	1.62 × 10–5	(3.92 ± 2.54) × 10–4	2.42 × 10
9	S-m3-HwTx-IV	(1.43 ± 0.06) × 10–2	3.57 × 10–4	(8.12 ± 0.04) × 10–7	2.28 × 10–3
12	[m3-HwTx-IV]-[PEG80]	(1.32 ± 0.11) × 10–2	nd	nd	nd

^aτ_on is the time constant wash-in. k_on* = 1/τ_on. k_on = (1/τ_on – k_off)/[ligand]. k_off = 1/τ_off, determined within an experimental washout time of 25 min. K_d = k_off/k_on. Kinetic data were determined using peptide concentrations equivalent to 10 times their IC₅₀ values, and k_on* and k_off are given as the mean ± SEM of three to five independent experiments.

^bk_off is less than the lowest valid measurement under the chosen experimental conditions.