HYDROGEN-PEROXIDE INDUCES PROTECTION AGAINST LETHAL EFFECTS OF CUMENEHYDROPEROXIDE IN ESCHERICHIA-COLI-CELLS - AN AHP DEPENDENT AND OXYR INDEPENDENT SYSTEM

Pretreatment with 2.5 mM H2O2 protects bacterial cells against cumene hydroperoxide killing. This response is independent of the OxyR system , but possibly involves the participation of Ahp protein, since ahp mu tants are not protected. Treatment of bacterial cells with high H2O2 c oncentrations caused an alteration on the electrophoretic profile of t he smaller subunit (22-kDa) of Ahp. This alteration does not require n ovel gene products and is not dependent on the OxyR protein. In this w ay, we propose that the modification of the 22-kDa subunit of Ahp by h igh H2O2 concentration may be responsible for the protection against t he lethal effects of cumene hydroperoxide. (C) 1998 Elsevier Science B .V. All rights reserved.