Synthesis, solution structure, and phylum selectivity of a spider delta-toxin that slows inactivation of specific voltage-gated sodium channel subtypes.

ABSTRACT: Magi 4, now renamed delta-hexatoxin-Mg1a, is a 43-residue neurotoxic peptide from the venom of the hexathelid Japanese funnel-web spider (Macrothele gigas) with homology to delta-hexatoxins from Australian funnel-web spiders. It binds with high affinity to receptor site 3 on insect voltage-gated sodium (Na(V)) channels but, unlike delta-hexatoxins, does not compete for the related site 3 in rat brain despite being previously shown to be lethal by intracranial injection. To elucidate differences in Na(V) channel selectivity, we have undertaken the first characterization of a peptide toxin on a broad range of mammalian and insect Na(V) channel subtypes showing that delta-hexatoxin-Mg1a selectively slows channel inactivation of mammalian Na(V)1.1, Na(V)1.3, and Na(V)1.6 but more importantly s

SUBMITTER: Yamaji N 

PROVIDER: S-EPMC2782047 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature