Potent insecticidal toxin that binds to two distinct sites in insect sodium channels, with close affinity (Kd1=34.7 pM and Kd2=35.1 pM) (PubMed:26220799). Its association is rather fast (1.4 and 8.5 minutes, respectively for sites 1 and 2) and its dissociation is a slower process (5.4 and 32.8 minutes, respectively) (PubMed:26220799). On rat brain synaptosomes the toxin partially competes (~30%) with the beta-toxin CssIV, but does not compete with the alpha-toxin AaII, nor with the beta-toxin Ts VII (PubMed:26220799). On cockroach nerve cord synaptosomes, the toxin does not compete with the anti-insect toxin LqqIT1, but it competes with the 'alpha-like' toxin BomIV (IC(50)=80 pM) (PubMed:26220799). In cockroach neurons, the toxin inhibits the inactivation of sodium channels and it shifts the sodium channel activation to hyperpolarizing potentials (PubMed:26220799). Hence, it behaves like an 'alpha-like' toxin and binds preferentially to site 3 on the insect Nav channel, located on the domain IV (PubMed:26220799). The toxin may also inhibit the N-methyl-D-aspartate (NMDA)-subtype of ionotropic glutamate receptor (GRIN) (By similarity). In vivo, the toxin causes excitatory effects on insects (PubMed:26220799). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. LD(50) is 4 nmol/g in flies (M.domestica). LD(50) is 230 pmol/g in cockroaches (P.americana). Is not toxic to mice (30 ug per mouse tested by intracerebroventricular injection). Belongs to the neurotoxin 03 (Tx2) family. 05 subfamily.