SUBUNIT SITES OF OXIDATIVE INACTIVATION OF ESCHERICHIA-COLI F1-ATPASE BY HOCL

Cellular inactivation of Escherichia coli by the neutrophil-generated toxin, hypochlorous acid, is accompanied by inactivation of its plasma membrane-localized F-1-ATPase. The nature of oxidative damage leading to inactivation of this enzyme was probed by SDS-PAGE and 2D-gel electrophoresis and by hybrid reconstitution studies using purified subunits from untreated and extensively oxidized bacteria. The data indicate that inactivation is due to selective oxidation of a few highly vulnerable sites; although damage occurred to each of the alpha, beta, and gamma-subunits required for soluble ATP hydrolase activity, the extent of damage was insufficient to alter their electrophoretic properties. (C) 1995 Academic Press, Inc.