Format

Send to

Choose Destination
See comment in PubMed Commons below
Biophys J. 2003 Apr;84(4):2416-26.

Puroindolines form ion channels in biological membranes.

Author information

  • 1Centre de Recherche de Biochimie Moléculaire, CNRS UPR 1086, UFR 24, 1919, 34293 Montpellier, France. charnet@crbm.cnrs-mop.fr

Abstract

Wheat seeds contain different lipid binding proteins that are low molecular mass, basic and cystine-rich proteins. Among them, the recently characterized puroindolines have been shown to inhibit the growth of fungi in vitro and to enhance the fungal resistance of plants. Experimental data, using lipid vesicles, suggest that this antimicrobial activity is related to interactions with cellular membranes, but the underlying mechanisms are still unknown. This paper shows that extracellular application of puroindolines on voltage-clamped Xenopus laevis oocytes induced membrane permeabilization. Electrophysiological experiments, on oocytes and artificial planar lipid bilayers, suggest the formation, modulated by voltage, of cation channels with the following selectivity: Cs(+) > K(+) > Na(+) > Li(+) > choline = TEA. Furthermore, this channel activity was prevented by addition of Ca(2+) ions in the medium. Puroindolines were also able to decrease the long-term oocyte viability in a voltage-dependent manner. Taken together, these results indicate that channel formation is one of the mechanisms by which puroindolines exert their antimicrobial activity. Modulation of channel formation by voltage, Ca(2+), and lipids could introduce some selectivity in the action of puroindolines on natural membranes.

PMID:
12668449
PMCID:
PMC1302807
DOI:
10.1016/S0006-3495(03)75046-2
[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center