Table 2.

Rates of recovery from block during washout of ligand(s) from binary and ternary complexes, corresponding to k_BR and k_AR and approximation of k_CB of Fig. 1C, respectively

	koff of complex, min−1†
Alkaloid	KIIIA·X·NaV	KIIIA[K7A]·X·NaV	X·NaV	Reference
None	0.0016 ± 0.0016	0.015 ± 0.005	—	Zhang et al. (2009)
TTX	0.020 ± 0.005 (0.017 ± 0.002)	0.024 ± 0.004 (0.025 ± 0.003)	2.2 ± 0.3	Zhang et al. (2009)
STX	0.350 ± 0.039 (NA)‡	0.014 ± 0.002 (0.015 ± 0.007)	2.0 ± 0.3	This study
GTX2/3	0.029 ± 0.001 (NA)‡	0.014 ± 0.003 (0.018 ± 0.005)	0.6 ± 0.08	This study

Values are means ± SD, n ≥3 oocytes.

^†Rate constants of recovery from block during washout of toxin(s) following exposure to: each peptide alone (top data row), or each alkaloid alone (right data column), or both alkaloid and peptide (remaining data entries). Ternary complexes were formed by exposure first to alkaloid as in Fig. 2, E and F (or exposure first to peptide as in Fig. 2D), followed by mixture of alkaloid plus peptide. Values of k_off were obtained by fitting the time course of recovery of activity after toxin(s) were washed out to a single-exponential curve, values without parentheses are those of the complex formed by exposure to alkaloid first, and values in parentheses are those of the complex formed by exposure to peptide first.

^‡NA, not available because ternary complex was not readily formed by adding peptide first.