Three-finger toxins in snake venoms consist of a multitude
of pharmacologically active peptides having a very similar
three-dimensional structure, with three loops extending from a
very conserved core rich in disulphide bridges [1]. According to
the diversity of their functions, three-finger toxins can be classified
into two major groups: neurotoxins and CTXs (cardiotoxins).
LNTXs (long-chain neurotoxins), SNTXs (short-chain
neurotoxins),WNTXs(weak neurotoxins) andMTXs(muscarinic
toxins) belong to the neurotoxin group, members of which interfere
in the transmission of nervous impulses by selectively binding
to particular receptors in the nerve or muscular membrane.
LNTXs and SNTXs are also called α-neurotoxins. They have
a high affinity for nAChRs (nicotinic acetylcholine receptors),
whereas MTXs bind to mAChRs (muscarinic acetylcholine
receptors) [2,3]. WNTXs are characterized by their being able to
act on nAChRs with a lower affinity than LNTXs [4]. The major
members of the CTX group have no known effect on nAChRs or
mAChRs, but exhibit quite different pharmacological properties,
such as cytolysis, haemolysis and heart failure [5].