I know that sodium azide and 2,4-DNPH inhibit proton pumps. The azide is called an inhibitor and 2,4-DNP is called uncoupler. I want to know what's the difference between the mechanisms of action of sodium azide and 2,4-DNPH in proton pumps. Why is one called an inhibitor and the other an uncoupler?


There's a decent presentation here that basically goes over what you're asking.

As an inhibitor, azides are similar to cyanide in that they inhibit complex IV by binding cytochrome oxidase, resulting in a sort of chemical asphyxiation.

Uncouplers are a little harder to wrap your head around. They embed in the membrane space, and we know that ETC and proton pumping depends on the established proton gradient across a membrane. Uncouplers uncouple the proton gradient from the electron transport chain, allowing protons to diffuse across the membrane, effectively negating the proton gradient.

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  • $\begingroup$ Isn't OP asking about protein pumps? This answer seems to focus on ATPases. It's just all in the name, but just wondering. $\endgroup$ – AliceD Feb 9 '16 at 8:25
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    $\begingroup$ The question is weird because when i think proton pump inhibitor, i think like omeprazole or benzimidazole derivatives which block the ATPase. I think the title is just misguided, because the compounds in the question body inhibit the electron transport chain. $\endgroup$ – CKM Feb 9 '16 at 13:17

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