Intracellular location of catalase-peroxidase hydroperoxidase I of Escherichia coli

The catalase-peroxidase hydroperoxidase I of Escherichia coli has been conf irmed to be located in the cytoplasm using two independent methods. Catalas e activity was found predominantly ( > 95%) in the cytoplasmic fraction fol lowing spheroplast formation. The cytoplasmic enzyme glucose-6-phosphate de hydrogenase and the periplasmic enzyme alkaline phosphatase were used as co ntrols. The second method of immunogold staining for the enzyme in situ rev ealed an even distribution of the enzyme across the cell. (C) 1999 Federati on of European Microbiological Societies. Published by Elsevier Science B.V . All rights reserved.