t-PLTXII corresponds to a membrane-tethered toxin protein whose design (PMID:15294139) is based on the structure of the lynx1-like gene family, and consists of a Tag:SS(lynx1) secretory signal sequence, the Plectreurys tristis PLTXII toxin peptide sequence (a toxin that acts to inhibit insect presynaptic Ca[2+] ion channels), a hydrophilic linker and a Tag:GPI(lynx1) anchor (this anchor sequence should result in the protein being tethered to the plasma membrane, limiting its activity to the cells in which it is expressed). The t-PLTXII tethered toxin can thus be used as a cell-autonomous inhibitor of insect presynaptic Ca[2+] ion channel (and hence neuronal cell) activity.