Interaction of phospholipid bilayers with polyamines of different length.

The tip-dip patch clamp method was used to study the effect of three polyamines, putrescine, spermidine and spermine, on bilayer lipid membrane (BLM) stability. Two kinds of mixed lipid-polyamine membranes were investigated. The poration voltage (V(p)), and the closed (sigma(cl)) and open (sigma(op)) state conductances for pure and polyamine-treated lipid membranes were determined by the method of current-voltage surfaces. It was demonstrated that putrescine and spermidine destabilized lipid membranes under all circumstances. BLM stabilization by spermine was observed when it was added to preformed membranes.