Phenoxyacetic acid induces glutathione-dependent detoxification and depletes the glutathione pool in Penicillium chrysogenum.
Enzymes of the glutathione-dependent detoxification pathway (glutathione S-transferase and gamma-glutamyl-transpeptidase) were induced, and the glutathione pool was completely depleted by phenoxyacetic acid in Penicillium chrysogenum mycelia incubated for 15 h in a culture medium containing lactose as a carbon source and sodium glutamate as a nitrogen source. A significant increase in both the oxidised glutathione concentrations and the glutathione reductase activities were also observed. 1-Chloro-2,4-dinitrobenzene--a potent substrate and inducer of glutathione S-transferase-initiated very similar physiological changes but no beta-lactam production could be detected in this case. When (NH4)2HPO4 was used as a nitrogen source the penicillin biosynthesis was repressed and the induction of gamma-glutamyltranspeptidase by phenoxyacetic acid was hindered considerably.
Emri
T
T
Department of Microbiology and Biotechnology, Kossuth Lajos University, Debrecen, Hungary.
Pócsi
I
I
Szentirmai
A
A
D004790:Enzyme Induction; D005978:Glutathione / Q000378:metabolism*; D005982:Glutathione Transferase / Q000096:biosynthesis; D008658:Inactivation, Metabolic; D007769:Lactams / Q000378:metabolism; D010408:Penicillium chrysogenum / Q000187:drug effects / Q000378:metabolism*; D010642:Phenoxyacetates / Q000494:pharmacology*; D005723:gamma-Glutamyltransferase / Q000096:biosynthesis
D007769:Lactams; D010642:Phenoxyacetates; D005723:gamma-Glutamyltransferase; D005982:Glutathione Transferase; D005978:Glutathione