From Bioblast
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 Β΅L. This now (2021-01-22) has been corrected to our previous recommendation of 1 M KCN stock solutions
Preparation of KCN stock
- Kcn(KCN): Fluka 60178, 100 g, store at R.T.; FW = 65.12.
- Caution: KCN is photosensitive and hygroscopic; HCN is volatile and very toxic!
- Preparation of 0.5 M KCN stock solution (dissolved in H2O):
- Weigh 32.6 mg of KCN.
- Dissolve in 1 ml H2O.
- The pH of the solution is basic. Since the titration amount is low and HCN may evaporate during pH adjustment with HCl, the pH is not adjusted.
- Divide into 0.2 mL portions
- Store at -20 Β°C.
- Β» O2k manual titrations MiPNet09.12 O2k-Titrations
- Titration volume (2-mL O2k-chamber): 4 Β΅L using a 10 Β΅L Hamilton syringe.
- Titration volume (0.5-mL O2k-chamber): 1 Β΅L using a 10 Β΅L Hamilton syringe.
- Final concentration: 1 mM.
- Β» O2k manual titrations MiPNet09.12 O2k-Titrations
MitoPedia topics: Inhibitor