Cyanide

high-resolution terminology - matching measurements at high-resolution

Cyanide

Description

Cyanide (usually added as KCN) is a competitive inhibitor of cytochcrome c oxidase (CIV). Inhibition is reversed by pyruvate and high oxygen levels.

Abbreviation: KCN

Reference: MiPNet09.12

MitoPedia topics: Inhibitor 

Application in HRR

Last update 2021-01-22

Inhibitor titrations, CIV-assay, alternative oxidase and ROX

• Cyanide and determination of residual oxygen consumption (ROX).
• Complex IV assay
• alternative oxidase

Caution: Due to a confusion, a change in the procedure for preparing the KCN was done in April 2019 that recommended to prepare 20 mM KCN stock and titrate 100 µl. This now have been corrected to our previous recommendation of 1 M KCN stock solutions

O2k manual titrations MiPNet09.12 O2k-Titrations

• Titration volume: 2 µl of 1 M stock, using a 10 µl syringe (2 ml O2k-chamber).
• Final concentration: 1 mM.

Preparation of KCN stock

Kcn(KCN): Fluka 60178, 100 g, store at R.T.; FW = 65.12.

Caution: KCN is photosensitive and hygroscopic; KCN is volatile and very toxic!

Preparation of 1 M KCN stock solution for 2-mL O2k-chamber

1. Weigh 13 mg of KCN.
2. Dissolve in 0.2 ml H₂O.
3. The pH of the solution may be very alkaline - adjust to physiological pH with HCl.

» O2k manual titrations MiPNet09.12 O2k-Titrations

• Titration volume (2-mL O2k-chamber): 100 µL using a 100 µL Hamilton syringe.

• Final concentration: 1 mM.

Preparation of 250 mM KCN stock solution (in 45 mM Trizma base) for 0.5-mL O2k-chamber:

1. Weigh 16,28 mg of KCN and dissolve in 1 mL of 45 mM Trizma base.
2. Divide into 200 µL aliquots (use dark glass vials).
3. Store frozen at -20 °C.

» O2k manual titrations MiPNet09.12 O2k-Titrations

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

MitoPedia topics: Inhibitor