Redox loops and proton pumps.
In a Review-Hypothesis, Mitchell [(1987) FEBS Lett. 222,235-245] has recently suggested possible molecular mechanisms for proton translocation by cytochrome oxidase. In describing these mechanisms, he extended his own concept of a redox loop in a manner expected to lead to confusion. He also stated that the term redox-linked proton pump implies an indirect coupling between electron transfer and proton translocation, and that this type of coupling is very difficult to test experimentally. Here it is argued that the original meaning of a redox loop should be maintained, and proper definitions of the terms redox-linked proton pump and direct or indirect coupling are formulated. In addition, it is reasoned that both types of coupling are amenable to experimental tests.
Malstrom
B G
BG
Department of Biochemistry, University of Goteborg, Sweden.
D003576:Electron Transport Complex IV / Q000378:metabolism*; D010084:Oxidation-Reduction; D011522:Protons; D012107:Research Design
D011522:Protons; D003576:Electron Transport Complex IV