The crotamine-myotoxin family is composed of small basic peptides (42 to 45 residues) from rattlesnakes venom that possess multiple functions. These toxins act as cell-penetrating peptides (CPP), and as potent voltage-gated potassium channel (Kv) inhibitors. They also exhibit antimicrobial activities and provoke hind limb paralysis (
Oguiura et al., 2005
). Muscle necrosis has also been reported (
Hayashi et al., 2008
), but this activity may be due to a possible contamination. Hence, this activity should be re-tested .
The representative of this family,
(from Crotalus durissus terrificus) has a compact fold with an α-helix and a two-stranded anti-parallel β-sheet. These are connected to each other and the remainder of the polypeptide chain by three disulfide bonds, which also form part of a central hydrophobic core. The global fold and the cysteine-pairing pattern of crotamine are similar to the
Fadel et al., 2005
). Hence, it is not surprising that β-defensins and crotamine share similar properties, including antibacterial activity and interaction with lipid membranes.
Voltage-gated potassium channel impairing toxin
This protein family in
Kerkis et al., 2010
SIB Swiss Institute of Bioinformatics