MPP+ toxicity in E. coli under aerobic and anaerobic conditions.
MPP+ and paraquat (PQ+2) are two structurally analogous and highly toxic pyridinium compounds. The mechanism of PQ+2 toxicity is best understood in the bacterial model system. While numerous studies, in a variety of systems, have indicated the causative role of free radicals and other oxygen-derived active species in PQ+2 toxicity, this question is yet unresolved in the case of MPP+. In this study we have used the E. coli model and have demonstrated that MPP+ is toxic to bacterial cells in a dose and time dependent modes. Additionally, it is shown that only in the presence of molecular oxygen, bacterial inactivation occurred. The protective effects of the chemical scavenger--mannitol--and of histidine are presented. These results are in complete accord with a free radical mechanism for MPP+ toxicity.
Haskel
Y
Y
Department of Cellular Biochemistry, Hebrew University, Jerusalem, Israel.
Udassin
R
R
Chevion
M
M
D015655:1-Methyl-4-phenylpyridinium / Q000633:toxicity*; D004926:Escherichia coli / Q000187:drug effects*; D016166:Free Radical Scavengers; D005609:Free Radicals; D006639:Histidine / Q000494:pharmacology; D008353:Mannitol / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology*
D016166:Free Radical Scavengers; D005609:Free Radicals; D008353:Mannitol; D006639:Histidine; D015655:1-Methyl-4-phenylpyridinium; D010100:Oxygen