Antimycin A

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Antimycin A

Description

Antimycin A is an inhibitor of Complex III (CIII). It binds to the Qi site of CIII and inhibits the transfer of electrons from heme b_H to oxidized Q (Qi site inhibitor). High concentrations of antimycin A also inhibit acyl-CoA oxidase and D-amino acid oxidase.

Abbreviation: Ama

Reference: MiPNet09.12

Application in HRR

Ama: Antimycin A (from Streptomyces sp.) Sigma A 8674, 25 mg, store at -20 °C: FW = 540

Caution: Very toxic. Chemicals stored in the fridge or freezer should be allowed to reach room temperature before opening.

Preparation of 5 mM stock solution (dissolved in 99.9% ethanol) for 2-mL O2k-chamber:

1. Weigh 5.4 mg of antimycin A into a small glass vial. Caution: Ama is hygroscopic.
2. Add 2 mL ethanol.
3. Divide into 0.2 mL portions in clear glass vials.
4. Store at -20 °C.

» O2k manual titrations MiPNet09.12 O2k-Titrations

• Titration volume (2-mL O2k-chamber): 1 µL using a 10 µL Hamilton syringe.
• Final concentration: 2.5 µM.

Preparation of 1,25 mM stock solution (dissolved in 99.9% ethanol) for 0.5-mL O2k-chamber:

1. Take 100 µL of the 5 mM stock solution.
2. Add 300 µL ethanol.

» O2k manual titrations MiPNet09.12 O2k-Titrations

• Titration volume (0.5-mL O2k-chamber): 1 µL using a 10 µL Hamilton syringe.
• Final concentration: 2.5 µM.

Microalgae applications

For the specific case of microalgal cells it is recommended to prepare higher concentration:

Preparation of 10 mM stock solution (dissolved in 99.9% ethanol)

1. Weigh 10.8 mg of antimycin A and dissolve in 2 mL of ethanol absolute (99.9%).
2. Divide into 0.2 mL portions in clear glass vials.
3. Store at -20 °C.

» O2k manual titrations MiPNet09.12 O2k-Titrations

• Titration volume (2-mL O2k-chamber): 8 µL using a 10 µL syringe.
• Final concentration: 40 µM.

Compare

• Myxothiazol - this CIII inhibitor induces less ROS production but is more expensive than Ama.

Antimycin A and ROS production

• Is hydrogen peroxide production measured after inhibition of the Electron transfer-pathway by rotenone and antimycin A of diagnostic significance? - Please, share your evidence (Email to [email protected]).

Inhibition of acyl-CoA oxidase and D-amino acid oxidase

• Vamecq J, Schepers L, Parmentier G, Mannaerts GP (1987) Inhibition of peroxisomal fatty acyl-CoA oxidase by antimycin A. Biochem J 248:603-7. - »Bioblast link«

MitoPedia topics: Inhibitor