Cytoplasmic membrane is the target organelle for transition metal mediated damage induced by paraquat in Escherichia coli
Bacterial survival indicates that copper or iron is an essential mediator in paraquat toxicity in Escherichia coli. In this study the authors have identified the cytoplasmic membrane as a target organelle in metal-mediated paraquat toxicity and have demonstrated the complete correlation of the membrane damage with the levels of adventitious copper (or iron). The extent of membrane damage was related by use of four parameters: (a) the level of cellular ATP, (b) the level of cellular potassium, (c) the cellular capacity to accumulate and retain radiolabeled leucine, and (d) the cellular integrity as reflected by transmission electron microscopy (TEM). Exposure of bacterial cells to a combination of paraquat and copper caused a marked decline in parameters a, b, and c. This decline was found to occur in parallel with, or even to precede, the sharp loss of survival of E. coli under the same conditions. Likewise, TEM micrographs clearly indicated alternations in cellular structure that possibly reflect sites of detachment of the cytoplasmic membrane from the bacterial capsule. In contradistinction, copper alone or paraquat alone could not bring about similar changes in cellular structure. These findings are in accord with the suggested site-specific metal-mediated Haber-Weiss mechanism for paraquat toxicity and support our notion that specific chelators of transition metals could reduce or prevent the biological deleterious effects of this herbicide.
- Research Organization:
- Hebrew Univ. of Jerusalem (Israel)
- OSTI ID:
- 5195041
- Journal Information:
- Biochemistry; (United States), Vol. 27:7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Paraquat toxicity is attenuated by 4-phenylbutyrate-induced phosphorylation of ERK2 via PI3K in A549 cells
Cytotoxicity and genotoxicity caused by yttrium oxide nanoparticles in HEK293 cells
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BIPYRIDINES
TOXICITY
CARBON 14 COMPOUNDS
UPTAKE
METALS
ATP
CATALASE
CATIONS
CELL MEMBRANES
COPPER COMPOUNDS
ESCHERICHIA COLI
HERBICIDES
INACTIVATION
IRON COMPOUNDS
LEUCINE
POTASSIUM COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
ALKALI METAL COMPOUNDS
AMINO ACIDS
AZINES
BACTERIA
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHARGED PARTICLES
ELECTRON MICROSCOPY
ELEMENTS
ENZYMES
HETEROCYCLIC COMPOUNDS
IONS
LABELLED COMPOUNDS
MEMBRANES
MICROORGANISMS
MICROSCOPY
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
PEROXIDASES
PESTICIDES
PYRIDINES
TRANSITION ELEMENT COMPOUNDS
560300* - Chemicals Metabolism & Toxicology
550701 - Microbiology- Tracer Techniques