Affects the activity of both ryanodine-sensitive calcium-release channels RyR1 and RyR2 with high potency. At lower concentrations the toxin increases full openings of the RyRs, and at higher concentrations it inhibits full openings and induce openings to subconductance levels and reduces the number of full conductance openings. The different actions may be attributed to the toxins binding at different sites on the RyRs, with binding at a high-affinity site mediating the increase in full openings and the induction of subconductance states evoked upon binding to a lower-affinity site. Insect-selective toxin that provokes a dose-dependent contractile paralysis in crickets and blowfly larvae, followed by death. Expressed by the venom gland. Structure of this peptide is made of two-stranded beta-sheets (or DDH for disulfide-directed beta-hairpin) that is uncommon for a scorpion-venom peptide, since it does not contain the CSalpha/beta, CSalpha/alpha, or knottin motif common to other disulfide-rich scorpion toxins. This structure may be the evolutionary precursor to the knottin motif. Monoisotopic mass. LD(50) is 784 pmol/g of when injected into mealworm, LD(50) is 1284 pmol/g of when injected into cricket, LD(50) is 4382 pmol/g of when injected into blowfly larvae, LD(50) is 4995 pmol/g of when injected into blowfly adult. Phi-liotoxin-Lw1a may reach its physiological target by traversing membranes, which may be by slow permeation. Alternatively, scorpion venoms are known to contain amphipathic helical peptides that form pores in the cell membrane, and it is possible that these pores would allow Phi-liotoxin-Lw1a to enter the cell (PubMed:23671114). Has no significant effects on sodium (Nav), potassium (Kv) and calcium (Cav) currents (PubMed:21670253 and PubMed:23671114).