Antioxidant Properties of α-Crystallin

α-Crystallin is a major chaperone lens protein to which has been ascribed antioxidant functions. In the present work we have evaluated the antioxidant and free radical scavenging properties of bovine α-crystallin in a series of in vitromodels: zimosan-induced, luminol-enhanced chemiluminescence 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 α-crystallin is higher than or similar to that of bovine serum albumin. It is concluded that, given the high concentrations of α-crystallin in the lenses, its capacity to interact with free radicals and to remove hypochlorous acid could contribute to the maintenance of the lens functionality.