Template:SUIT KCN

Cyanide (usually added as KCN) is a competitive inhibitor of cytochrome c oxidase (CIV). In the presence of an active alternative oxidase (AOX) pathway, after the inhibition of CIV, cells remain in the physiological coupling state ROUTINE. In those occasions where the AOX is not active, after the inhibition of CIV, the (ROX state) is normally achieved, where Rox is the residual oxygen consumption due to oxidative side reactions estimated either after inhibition of CIII, CIV or in the absence of endogenous fuel-substrates. Rox is subtracted from oxygen flux as a baseline for all respiratory states, to obtain mitochondrial respiration. Cyanide inhibition is reversed by pyruvate and high oxygen levels.