Polyamine binding to phospholipid vesicles and inhibition of lipid peroxidation

A study of the possible mechanism of inhibition by polyamines of lipid peroxidation was made utilizing vesicles prepared with mixed soy bean phospholipids. The results obtained can be summarized as follows: 1) Polyamines inhibit lipid peroxidation only when bound to the negative charges on vesicle surface. 2) Polyamines inhibit lipid peroxidation at concentrations lower than those required to cause precipitation of the vesicles and similar to those required for formation of the polyamine/phospholipid vesicle complex. 3) Spermine bound to vesicles, in contrast to free spermine, highly decreases the reactivity of both Fe2+ and Fe3+ versus superoxide.