. Author manuscript; available in PMC: 2020 Jul 11.

Published in final edited form as: J Med Chem. 2019 Jun 27;62(13):6262–6275. doi: 10.1021/acs.jmedchem.9b00566

Table 1.

Amino Acid Sequences and Potencies of Select α-Ctxs that Target α3β2 and α6/α3β2β3 nAChRs^a

		α3β2 nAChR	α6/α3β2β3 nAChR

α-Ctx	Sequence	IC₅₀ values (nM)		Ratio
PeIA	GCCSHPACSVNHPELC	19.4 (15.3–24.6) ^b	19.8 (17.9–21.8) ^b	1
PnIA	GCCSLPPCAANNPDYC	7.7 (6.8–8.8) ⁽⁴¹⁾	10.9 (7.9–14.9) ⁽⁴²⁾	1
OmIA	GCCSHPACNVNNPHICG	11.0 (7.1–17.0) ⁽¹⁵⁾	201 (101–401) ⁽²⁴⁾	18
LvIA	GCCSHPACNVDHPEIC	8.7 (6.9–11.0) ⁽²⁵⁾	108 (54–215) ⁽²⁵⁾	12
MII	GCCSNPVCHLEHSNLC	2.2 (1.2–3.8) ⁽⁴³⁾	0.4 (0.3–0.5) ⁽³⁰⁾	0.6
LtIA	GCCARAACAGIHQELC	9.8 (7.3–13.2) ⁽⁴⁴⁾	84.4 (58–123) ⁽⁴⁴⁾	9

Residues highlighted in yellow are conserved among these α-Ctxs. IC₅₀ values are from electrophysiology experiments using X. laevis oocytes heterologously expressing cloned rat nAChRs; values in parentheses indicate the 95% confidence interval; selectivity was calculated as the IC50 ratio of (α6/α3β2β3)/(α3β2).

This work.