Menadione effect on l-cysteine desulfuration in U373 cells.
The non-cytotoxic concentration (20 microM) of menadione (2-methyl-1,4-naphthoquinone), after 1 h of incubation, leads to loss of the activity of rhodanese by 33%, 3-mercaptopyruvate sulfurtransferase by 20%, as well as the level of sulfane sulfur by about 23% and glutathione by 12%, in the culture of U373 cells, in comparison with the control culture. Reactive oxygen species generated by menadione oxidize sulfhydryl groups in active centers of the investigated enzymes, inhibiting them and saving cysteine for glutathione synthesis. A decreased sulfane sulfur level can be correlated with an oxidative stress.
Wróbel
Maria
M
Chair of Medical Biochemistry, Jagiellonian University Medical College, Kraków, Poland. mbwrobel@cyf-kr.edu.pl
Jurkowska
Halina
H
D002460:Cell Line; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism; D013455:Sulfur / Q000737:chemistry; D013466:Sulfurtransferases / Q000037:antagonists & inhibitors; D013884:Thiosulfate Sulfurtransferase / Q000037:antagonists & inhibitors; D024483:Vitamin K 3 / Q000494:pharmacology* / Q000633:toxicity
D017382:Reactive Oxygen Species; D013455:Sulfur; D024483:Vitamin K 3; D013466:Sulfurtransferases; D013884:Thiosulfate Sulfurtransferase; C021550:3-mercaptopyruvate sulphurtransferase; D005978:Glutathione; D003545:Cysteine