TABLE 5

α -Conotoxin MII and analogs

Rat nAChRs were heterologously expressed in oocytes, and functional block of ACh-induced current was measured. Radioiodinated α -conotoxin MII was used with mouse brain homogenates to examine the competition binding of the indicated peptides. See Figs. 1, 2, 3, and 6. Numbers in parentheses are 95% confidence intervals.

Peptide IC50 Rat α3β2 IC50 Rat α6/α3β2β3 Ki Mouse CNS α-MII Site
nM
α-MII 2.2 (1.2-3.8) 0.39 (0.28-0.55) 0.22 (0.20-0.25)
MII[H9A] 59 (44-79) 0.79 (0.56-1.1) 1.1 (0.84-1.6)
MII[E11A] 8.7 (6.8-11.1) 0.16 (0.13-0.19) 0.27 (0.19-0.37)
MII[L15A] 34 (19-60) 0.92 (0.65-1.3) 0.30 (0.21-0.45)
MII[H9A;L15A] 4800 (3500-6600) 2.4 (1.7-3.4) 3.3 (2.5-4.3)