Functional and structural features of γ‐zeathionins, a new class of sodium channel blockers

Autor: Kushmerick, Christopher, de Souza Castro, Mariana, Santos Cruz, Jáder, Bloch, Carlos, Beirão, Paulo S.L.
Zdroj: FEBS Letters; December 1998, Vol. 440 Issue: 3 p302-306, 5p
Abstrakt: γ1‐ and γ2‐zeathionins (γ1‐Z and γ2‐Z) are members of a family of small and basic peptides involved in plant protection. These plant defensins exhibit remarkable structural similarity to scorpion neurotoxins and insect defensins. In the present report, we used the whole‐cell patch clamp technique to investigate the inhibition of the sodium current (INa) by γ1‐Z and γ2‐Z in the GH3 cell line. Both γ1‐Z and γ2‐Z rapidly and reversibly inhibited INawithout changing the kinetics or voltage dependence of activation or inactivation. To our knowledge, this is the first example of a plant protein that inhibits the sodium channel. From structural comparisons with the μ‐conotoxins, a family of peptides that block the sodium channel, we detected some similar features that could provide the basis of inhibition of sodium channels by γ‐zeathionins.
Databáze: Supplemental Index