DIFFERENTIAL-EFFECTS OF 5 TYPES OF ANTIPATHOGENIC PLANT PEPTIDES ON MODEL MEMBRANES

The effects of five antipathogenic plant peptides, wheat alpha-thionin , potato PTH1 defensin, barley LTP2 lipid transfer protein, and potato tuber DL1 and DL2 defensins, have been tested against phospholipid ve sicles (liposomes). Wheat thionin very actively induces aggregation an d leakage of negatively charged vesicles. LTP2 displays the same activ ities, although to a limited extent. Under certain conditions PTH1 and DL2 induce vesicle aggregation, but not leakage. Potato defensin DL1 failed to show any effect on liposomes. The same peptides have been as sayed against a plant pathogenic bacterium, both the membrane-active a nd -inactive compounds having efficient antibacterial action. (C) 1997 Federation of European Biochemical Societies.