Phospholipase A2 -: An enzyme that is sensitive to the physics of its substrate

A simple statistical mechanical model of lipid bilayers is proposed to account for the non-equilibrium action of the enzyme phospholipase A(2). The enzyme hydrolyses lipid-bilayer substrates and produces product molecules that lead to local variations in the bilayer interfacial pressure. Computer simulation of the model shows, in quantitative agreement with experimental data, that the enzyme activity is modulated by nano-scale lipid-domain formation in the lipid bilayer leading to a characteristic lag-burst behavior.