Protective effects of carnosine against protein modification mediated by malondialdehyde and hypochlorite.

Malondialdehyde (MDA) and hypochlorite anions are deleterious products of oxygen free-radical metabolism. The effects of carnosine, a naturally occurring dipeptide (beta-alanyl-L-histidine), on protein modification mediated by MDA and hypochlorite have been studied. MDA and hypochlorite induced formation of carbonyl groups and high molecular weight and cross-linked forms of crystallin, ovalbumin and bovine serum albumin. The presence of carnosine effectively inhibited these modifications in a concentration-dependent manner. It is proposed that relatively non-toxic carnosine and related peptides might be explored as potential therapeutic agents for pathologies that involve protein modification mediated by MDA or hypochlorite.