FCCP = carbonyl cyanide

Benz, R. and McLaughlin, S. (1983). The molecular mechanism of action of the proton ionophore FCCP (carbonyl cyanide p-trifluoromethoxyphenylhydrazone), Biophys. J., 41, 381-398. 

FAD - flavin adenine dinucleotide FCCP - carbonyl cyanide p-trifluoromethoxyphenyl-hydrazone... 

In addition to direct inhibition of the vesicular transport protein, storage of neurotransmitters can be reduced by dissipation of the proton electrochemical gradient. Bafilomycin (a specific inhibitor of the vacuolar H+-ATPase), as well as the proton ionophores carbonyl cyanide m-chlorophenylhydrazone (CCCP) and carbonylcyanide p-(trifluoromethoxy) phenylhy-drazone (FCCP) are used experimentally to reduce the vesicular storage of neurotransmitters. Weak bases including amphetamines and ammonium chloride are used to selectively reduce ApH. 

The uncoupler carbonyl cyanide p-(trifluoro-methoxy)phenylhydrazone (FCCP) and related compounds are widely used in biochemical studies. Their action can be explained only partially by increased proton conduction. 

Highly lipophilic weak acids and bases that have the capacity to remain lipophilic in both their protonated and deprotonated forms can act as protonophores. Such compounds belong to another class of ionophores that are often referred to as mitochondrial uncouplers because of their unique ability to translocate protons across mitochondrial membranes, resulting in the subsequent loss of the mitochondrial proton gradient that is required to drive oxidative phosphorylation. While certain natural products act as mitochondrial uncouplers, most of the protonophores used as pharmacological probes are not natural products but are low-molecular-weight synthetic compounds (e.g., carbonyl cyanide -trifluoromethoxyphenylhydrazone (FCCP)). 

Glycylsarcrosine, protonophore, such as carbonyl cyanide 4-trifluoromethoxy-phenylhydrazone (FCCP) and inhibitors of the Na + /H + exchanger, such as amiloride... 

As discussed above, the kidney is sensitive to different forms of oxidant-mediated injury. An early study su ested by Schnellmann and colleagues su ested that in PT cell suspensions, PARP activation did not play a role of acute renal PT cell injury and death caused by agents which cause oxidative stress. Specifically, suspensions of raH>it PT cells were exposed to antimycin A (a mitochondrial inhibitor), carbonyl cyanide p-(trifruoromethoxy)phenylhydiazone (FCCP, a protonophore) and tert-butyl hydroperoxide (t-BHP, an oxidant). No evidence of DNA fragmentation was observed with any of these agents durii cell death. ... 

Uncoupler-stimulated A -hyd lyti actiY ty is ex -bited in the presence of Mg, Cd, Co, Mn, and Zn, whereas no stimulation by carbonyl cyanide p-trifluorome thoxyphenylhydrazone (FCCP) occurs in the presence of Ca (Table 1). Furthermore, ATP- duce prot pum ng also occurs in the presence of Mg, Cd, Co, , and Zn... 

FCCP acronym of carbonyl cyanide-p-trifluorome-thoxyphenylhydrazone. See lonophore. 

The dye chosen may interact with elements of the system with a consequential change in its properties. Thus the pKa of a pH indicator in solution may not necessarily have the same value when the indicator is bound to cellular or other constituents (see, for example, (20, 21)) indeed the spectra of the bound dye may differ from those of the free dye, making any simple evaluation of pH problematical. It may be that the dye is useful as a qualitative indicator of the parameter under investigation but cannot be calibrated because it forms complexes with agents required in the calibration protocol It is always good practice to use several, independent calibration procedures to check for internal consistency of the dye response. Thus when calibrating optical probes of membrane potential (22, 23) the same values should be obtained when valinomydn/ K or uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP)/ are introduced. 

The identification of proton selectivity requires special attention because it can be difficult to detect and study in both planar bilayers and LUVs. In the HPTS assay, the apparent activity of proton transporters decreases with increasing H+ > M+ selectivity, because M+ antiport becomes more and more rate-limiting with increased selectivity. To solve this problem, vahnomycin can be added. " Recovered H+ transport activity in presence of the potassium carrier demonstrates H+ > K+ selectivity. Analogously, the proton carrier carbonyl cyanide 4-(trifiuoromethoxy)phenyIhydrazone (FCCP) has been used to confirm the M+ > H+ selectivity of, for example, amphotericin B. 

Protonophores such as carbonyl cyanide trifluoromethoxyphenyl hydrazone (FCCP) and 2,4-dinitrophenol (2,4-DNP) and metabolic inhibitors such as sodium azide are also known to inhibit these membrane redox systems (39, 57). Protonophores act by dissipating the proton motive force at the membrane which at low concentrations actually stimulates electron flow across membranes (4,22). A slight stimulation in TNT reduction was observed with FCCP, between 0 and 50 pM, but was not statistically significant. In general, TNT reduction was inhibited by these compounds at concentrations known to inhibit membrane redox systems. 

The adipocytes used as the test system for mammalian cells were grown in 96-well plates with the well-known respiratory uncoupler, carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) or the inhibitor of the respiratory chain, rotenone. The results reproduced in Figure 47 validated the analytical... 

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