Photosensitization of Wild and Mutant Strains ofEscherichia colibymeso-Tetra (N-methyl-4-pyridyl)porphine
| Autor: | Giorgio M. Giacometti, Barbara Breda, Elena Reddi, Giuliana Valduga, Giulio Jori |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Porphyrins
Time Factors DNA Repair Light DNA repair Mutant Biophysics medicine.disease_cause Biochemistry chemistry.chemical_compound Plasmid Cations Escherichia coli medicine Molecular Biology Adenosine Triphosphatases Photosensitizing Agents L-Lactate Dehydrogenase biology Cell Membrane Wild type NADH dehydrogenase NADH Dehydrogenase Cell Biology Molecular biology Transport protein Molecular Weight Oxygen Succinate Dehydrogenase chemistry Mutation biology.protein Ampicillin Electrophoresis Polyacrylamide Gel DNA Bacterial Outer Membrane Proteins Plasmids |
| Zdroj: | Biochemical and Biophysical Research Communications. 256:84-88 |
| ISSN: | 0006-291X |
| DOI: | 10.1006/bbrc.1999.0190 |
| Popis: | Wild type Escherichia coli cells as well as some mutant strains lacking specific DNA repair systems are efficiently killed upon visible light-irradiation after 5 min-incubation with meso-tetra(4N-methyl-pyridyl)porphine (T4MPyP). The presence of oxygen is necessary for cell photoinactivation. The porphyrin appears to exert its phototoxic activity largely by impairing some enzymic and transport functions at the level of both the outer and cytoplasmic membrane. Thus, SDS-PAGE electrophoresis shows a gradual attenuation of some transport protein bands as the irradiation proceeds, while a complete loss of lactate and NADH dehydrogenase activities is caused by 15 min-exposure to light. On the other hand, DNA does not represent a critical target of T4MPyP photosensitization as suggested by the closely similar photosensitivity of the wild E. coli and E. coli strains defective for two different DNA repair mechanisms, as well as by the lack of any detectable alteration of the pUC19 plasmids extracted from photosensitized E. coli TG1 cells. |
| Databáze: | OpenAIRE |
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