Juvenile Hormone: Effect on Bimolecular Lipid Membranes

Abstract

INSECT juvenile hormones and their synthetic analogues may function by increasing the permeability of cell and nuclear membranes^1,2. Recently it has been shown that some synthetic hormone analogues increase the conductance of the salivary gland cell membrane of the wax moth Galleria mellonella³. Because of this, I checked a number of compounds for their effect on the conductance of experimental bimolecular lipid membranes in an aqueous medium⁴. No significant conductance changes appeared on addition of the hormones to non-modified membranes. The membranes were therefore modified by gating ion translocators, such as EIM (excitability inducing material, extracted from Aerobacter cloacae ATCC 961), monazomycin⁵ or alamethicin⁶. These translocators induce ion permeability in lipid bilayers and this permeability can be regulated by the membrane potential although it is not known if the translocators act as ion carriers or form channels. In appropriate conditions they generate action potential and other excitability phenomena characteristic of cell membranes.