– Beta toxins bind voltage-independently at site-4 of sodium channels (Nav) and shift the voltage of activation toward more negative potentials thereby affecting sodium channel activation and promoting spontaneous and repetitive firing. Strongly affects skeletal muscle channels Nav1.4/SCN4A, poorly affects the neuronal channels Nav1.6/SCN8A and Nav1.2/SCN2A. Induces spastic paralysis of rear limbs, increased salivation, apnea, tachycardia and increased perspiration. Beta-toxin Tz1 Protein, Tityus zulianus, Recombinant (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 14.8 kDa and the accession number is Q2NME3.