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

Application in HRR

Inhibitor titrations, CIV-assay, alternative oxidase and ROX

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

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; KCN is volatile and very toxic! It is recommended to prepare fresh KCN solution although it can be safely stored at -20°C. To avoid KCN evaporation, it is recommended to use alkaline buffers (such as 45 mM Trizma base, pH >10).

Preparation of 45 mM Trizma base:

1. Weigh 545 mg of Trizma base
2. Dissolve it in 100 mL of H₂0.

Preparation of 20 mM KCN stock solution (in 45 mM Trizma base) for 2-mL O2k-chamber:

1. Weigh 5.2 mg of KCN and dissolve in 4 mL of 45 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 (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