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

Inhibitor titrations, CIV-assay, alternative oxidase and ROX

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

Preparation of 20 mM KCN stock (in 50mM Trizma base)

Kcn(KCN): Fluka 60178, 100 g, store at R.T.; FW = 65.12., Trizma base: Sigma T6066, 100 g, store at R.T.; FW = 121.14

Caution: KCN is photosensitive and hygroscopic; HCN is volatile and very toxic! Has to be prepared in 50 mM Trizma base to keep it in a high pH range and avoid any evaporation of the KCN. It is recommended to prepared fresh although it can be safely stored at -20°C

Preparation of 50 mM Trizma base:

1. Weigh 605.7 mg of Trizma base
2. Dissolve it in 100 mL of H₂0.

Preparation of 20 mM KCN:

1. Weigh 5.2 mg of KCN and dissolve in 4 ml of 50 mM Trizma base.
2. Divide into 500 µl aliquots (use dark glass vials).
3. Store frozen at -20 °C.

O2k manual titrations MiPNet09.12 O2k-Titrations

• Titration volume: 100 µl of 20 mM stock (2 ml O2k-chamber).
• Final concentration: 1 mM.