Antioxidant properties of alpha-crystallin

alpha -Crystallin is a major chaperone lens protein to which has been ascri bed antioxidant functions. In the present work we have evaluated the antiox idant and free radical scavenging properties of bovine alpha -crystallin in a series of in vitro models: zimosan-induced, luminol-enhanced chemilumine scence response of polymorphonuclear leukocytes, the autoxidation of brain homogenate, bleaching of 2,2 ' -azinobis(3-ethylbenzothiazoline-6-sulfonic acid)-derived radical cations, trapping of peroxyl radicals, and reactivity toward hypochloric acid. In all these systems, the reactivity of alpha -cr ystallin is higher than or similar to that of bovine serum albumin. It is c oncluded that, given the high concentrations of alpha -crystallin in the le nses, its capacity to interact with free radicals and to remove hypochlorou s acid could contribute to the maintenance of the lens functionality.