Myxothiazol

high-resolution terminology - matching measurements at high-resolution

Myxothiazol

Description

Myxothiazol Myx is an inhibitor of Complex III (CIII). CIII also inhibits CI. Myxothiazol binds to the Q_o site of CIII (close to cytochrome b_L) and inhibits the transfer of electrons from reduced QH₂ to the Rieske iron sulfur protein.

Abbreviation: Myx

Reference: MiPNet09.12

Application in HRR

Myx: Myxothiazol (from Myxobacterium myxococcus fulvus; C₂₅H₃₃N₃O₃S₂), Sigma-Aldrich: T5580, store at 4 °C, CAS: 76706-55-3, M = 487.7 g·mol^-1

Hazard statements: H300; fatal if swallowed

Available again from Sigma with this new product number. The old product number was M 5779.

Preparation of 1 mM storage and stock solution (dissolved in ethanol abs.) for 2-mL O2k-chamber:

1. Weigh 1 mg of myxothiazol into a small glass vial.
2. Add 2.05 mL ethanol.
3. Divide into 0.2 mL (use glass vials).
4. Store at -20 °C.

» Oroboros manual titrations MiPNet09.12 Manual titrations of SUIT chemicals

• Titration volume (2-mL O2k-chamber): 1 µL using a 10 µL Hamilton syringe.
• Experimental concentration: 0.5 µM.

Preparation of 0.25 mM stock solution (dissolved in ethanol abs.) for 0.5-mL O2k-chamber:

1. Take 100 µL of the 1 mM stock solution.
2. Add 300 µL EtOH.

» Oroboros manual titrations MiPNet09.12 Manual titrations of SUIT chemicals

• Titration volume (0.5-mL O2k-chamber): 1 µL using a 10 µL Hamilton syringe.
• Experimental concentration: 0.5 µM.

Compare

• Antimycin A is less expensive than Myx but induces higher ROS production.

References

• Kim H, Xia D, Yu C-A, Xia J-Z, Kachurin AM, Zhang L, Yu L, Deisenhofer J (1998) Inhibitor binding changes domain mobility in the iron–sulfur protein of the mitochondrial bc1 complex from bovine heart. Proc Natl Acad Sci U S A 95:8026-33. https://doi.org/10.1073/pnas.95.14.8026
• Starkov AA, Fiskum G (2001) Myxothiazol induces H(2)O(2) production from mitochondrial respiratory chain. Biochem Biophys Res Commun. 281:645-50. https://doi.org/10.1006/bbrc.2001.4409
• Von Jagow G, Engel WD(1981) Complete inhibition of electron transfer from ubiquinol to cytochrome b by the combined action of antimycin and myxothiazol. FEBS Lett 136:19-24. https://doi.org/10.1016/0014-5793(81)81206-9
• Von Jagow G, Ljungdahl PO, Graf P, Ohnishi T, Trumpower BL (1984) An inhibitor of mitochondrial respiration which binds to cytochrome b and displaces quinone from the iron-sulfur protein of the cytochrome bc1 complex. J Biol Chem 259:6318–26. https://doi.org/10.1016/S0021-9258(20)82143-7

MitoPedia topics: Inhibitor