A proposed function for spermine and spermidine: Protection of replicating DNA against damage by singlet oxygen

Abstract

Like all aliphatic amines, the polyamines spermine and spermidine are physical quenchers of singlet molecular oxygen (1O*2). The rate constants of these processes were determined in vitro with photochemically generated 1O*2 and the hydrocarbon rubrene as substrate, in pyridine. At millimolar concentration, spermine and spermidine should quench 1O*2 in vivo and prevent it from damaging DNA. It is proposed that a biological function of polyamines is the protection of replicating DNA against oxidative damage.