Beta-mammal toxin CeII-9 (CeII-9)

Centruroides elegans CeII9 (also known as Beta-mammal toxin CeII-9) is a potent neurotoxin isolated from the venom of the Mexican scorpion Centruroides elegans [1]. It belongs to the beta-class of scorpion toxins, which are characterized by their ability to modulate the gating mechanism of voltage-gated sodium channels (Nav) [2]. Specifically, CeII9 binds to neurotoxin receptor site 4 on the sodium channel, shifting the voltage-dependence of activation toward more hyperpolarized potentials and reducing the peak sodium current [1, 2]. This action causes the channels to open at more negative membrane potentials, leading to spontaneous and repetitive firing of action potentials in neurons and muscle fibers [3]. Clinically, this results in severe envenomation symptoms, including muscle spasms, respiratory distress, and cardiovascular instability [2]. While CeII9 is not a therapeutic target for treating human diseases, it is the primary target for neutralization by therapeutic antivenoms such as Alacramyn [2]. In pharmacological research, CeII9 is used as a high-affinity probe to investigate the structural biology of sodium channels and the molecular basis of channelopathies [1, 3].

Other names

Toxin CeII-9CeII9Centruroides elegans toxin 9

Neutralization of the toxin by specific antibody fragments, preventing its binding to voltage-gated sodium channels [2].