Studies on human porin. XVI: Polyamines reduce the voltage dependence of human VDAC in planar lipid bilayers--spermine and spermidine inducing asymmetric voltage gating on the channel.

We present the first data on the effects of polyamines on human VDAC. Purified VDAC in lipid bilayers shows lowered voltage dependence whenever putrescine, cadaverine, spermine, spermidine, or the histamine releaser Compound 48/80, respectively, are applied. Only spermine and spermidine induce an asymmetric reaction on the channel. However, we state a groupwise different reaction of polyamines, which are organic polycations, on human porin.