Myxothiazol, Myx, is an inhibitor of Complex III (CIII). CIII also inhibits CI (G. Lenaz). Myxothiazol binds to the Qo site of CIII (close to cytochrome bL) and inhibits the transfer of electrons from reduced QH2 to the Rieske iron sulfur protein.
MitoPedia topics: Inhibitor
Application in HRR
Myx: Myxothiazol (from Myxobacterium myxococcus fulvus, ~95%, HPLC), C25H33N3O3S2); Sigma T 5580, 1 mg, store at 4 °C: FW = 487.7. Available again from Sigma with this new product number. The old product number was M 5779.
Caution: Very toxic.
Preparation of 1 mM storage and stock solution (dissolved in 99.9% ethanol):
- Weigh 1 mg of myxothiazol into a small glass vial.
- Add 2.05 mL ethanol.
- Divide into 0.2 mL (use glass vials).
- Store at -20 °C.
O2k manual titrations MiPNet09.12
- Titration volume: 1 µL using a 10 µL syringe (2 mL O2k-chamber).
- Final concentration: 0.5 µM.
- Antimycin A is less expensive than Myx but induces higher ROS production.