Voltage-Gated Sodium Channels Are Targets for Toxinsfrom the Venom of the Spider Heriaeus melloteei

摘要

Three novel peptides were isolated from the venom of the spider Heriaeus melloteei (Thomisidae)and characterized. The peptides named Hm-1, 2 and 3 blocked voltage-gated Na~+channels at concentrations inthe order of 100 nM. Activity of the purified peptides was investigated in Na~+channel isoforms of mammalsand insects. Hm-1 and 2 appeared to act as pore blockers, whereas Hm-3 modulated the channel activation pro-cess. The toxins described exhibit minor similarity with other known peptides and may therefore constitute newgroups of Na~+