Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. This toxin potently and selectively blocks rat alpha-3-beta-2/CHRNA3-CHRNB2 nAChRs (IC(50)=9.8-22.95 nM) (PubMed:20145249, PubMed:34523332). Also shows a moderate block on rat alpha-6/alpha-3-beta-2-beta-3 (CHRNA6/CHRNA3-CHRNB2-CHRNB3) nAChRs (IC(50)=84.4 nM), and a weak activity on rat alpha-6/alpha-3-beta-4 (CHRNA6/CHRNA3-CHRNB4) nAChRs (IC(50)~6 uM) (PubMed:20145249). The block of alpha-3-beta-2/CHRNA3-CHRNB2 nAChRs is rapidly reversible (PubMed:20145249). It prevents alpha-conotoxin MII from blocking alpha-3-beta-2/CHRNA3-CHRNB2 nAChRs, suggesting that both toxins have overlapping binding sites (PubMed:20145249). In addition, this toxin shows a distinct nAChR binding mode from other alpha-conotoxins (PubMed:20145249). It potently blocks alpha-3-beta-2/CHRNA3-CHRNB2 nAChRs, although it lacks the highly conserved motif Ser-Xaa-Pro motif found in many other alpha-conotoxins to be crucial for potent nAChR interaction (PubMed:20145249). It seems to show relative flexibility in solution, wich is consistent with the absence of the conserved Ser and Pro residues that likely have a structure-defining role in other alpha-conotoxins (PubMed:20145249). Molecular docking simulations also suggest that this toxin has a surprisingly shallow binding site on the alpha-3-beta-2/CHRNA3-CHRNB2 nAChRs (PubMed:20145249). Expressed by the venom duct. The cysteine framework is I (CC-C-C). Alpha4/7 pattern. The fluorescent analog of LtIA (LtIA-F) is a highly selective molecule targeting alpha-3-beta-2/CHRNA3-CHRNB2 nAChR that could be used as a molecular probe for the study of the structure, function, and distribution of this receptor in live systems. It displays a ~4-fold decrease in potency towards alpha-3-beta-2/CHRNA3-CHRNB2 compared with native LtIA without a change in selectivity. Does not show activity on alpha-9-alpha-10/CHRNA9-CHRNA10, alpha-4-beta-2/CHRNA4-CHRNB2, alpha-4-beta-4/CHRNA4-CHRNB4, alpha-3-beta-4/CHRNA3-CHRNB4, alpha-2-beta-2/CHRNA2-CHRNB2, alpha-2-beta-4/CHRNA2-CHRNB4, alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE, and alpha-7/CHRNA7. Belongs to the conotoxin A superfamily.