Naja nigricollis three-finger cytotoxin (3FTx) (3FTx)

Naja nigricollis three-finger cytotoxins (3FTxs) are a group of small, basic, non-enzymatic proteins found in the venom of the black-necked spitting cobra, Naja nigricollis. These toxins are characterized by a conserved structural motif consisting of three beta-sheet loops extending from a central hydrophobic core, stabilized by four or five disulfide bonds [1]. Their primary biological function is the disruption of cell membranes through interaction with anionic phospholipids, leading to pore formation and rapid cell lysis [2]. In the context of envenomation, these cytotoxins are the principal agents responsible for severe local tissue necrosis and dermonecrosis, which can lead to permanent disability [3]. While traditionally neutralized by polyvalent antivenoms like SAIMR, research is increasingly focused on developing next-generation therapeutics, including monoclonal antibodies and small-molecule inhibitors like suramin, to more effectively mitigate the localized damage caused by these toxins [4, 5]. Understanding the specific binding kinetics of these 3FTxs is crucial for improving the efficacy of snakebite treatments in sub-Saharan Africa [3].

Other names

CardiotoxinCytotoxinMembrane-active polypeptideNaja nigricollis CTXCobramine

Direct disruption of the cell membrane lipid bilayer through binding to anionic phospholipids, resulting in pore formation and cytolysis [2, 3].