Krulwich T A, Quirk P G, Guffanti A A
Department of Biochemistry, Mount Sinai School of Medicine, City University of New York, New York 10029.
Microbiol Rev. 1990 Mar;54(1):52-65. doi: 10.1128/mr.54.1.52-65.1990.
The chemiosmotic model of energy transduction offers a satisfying and widely confirmed understanding of the action of uncouplers on such processes as oxidative phosphorylation; the uncoupler, by facilitating the transmembrane movement of protons or other compensatory ions, reduces the electrochemical proton gradient that is posited as the energy intermediate for many kinds of bioenergetic work. In connection with this formulation, uncoupler-resistant mutants of bacteria that neither exclude nor inactivate these agents represent a bioenergetic puzzle. Uncoupler-resistant mutants of aerobic Bacillus species are, in fact, membrane lipid mutants with bioenergetic properties that are indeed challenging in connection with the chemiosmotic model. By contrast, uncoupler-resistant mutants of Escherichia coli probably exclude uncouplers, sometimes only under rather specific conditions. Related phenomena in eucaryotic and procaryotic systems, as well as various observations on uncouplers, decouplers, and certain other membrane-active agents, are also briefly considered.
能量转导的化学渗透模型为解偶联剂对氧化磷酸化等过程的作用提供了一种令人满意且得到广泛证实的理解；解偶联剂通过促进质子或其他补偿离子的跨膜移动，降低了被认为是多种生物能量工作的能量中间体的电化学质子梯度。与此表述相关的是，既不排除也不使这些试剂失活的细菌解偶联剂抗性突变体代表了一个生物能量难题。事实上，需氧芽孢杆菌属的解偶联剂抗性突变体是具有生物能量特性的膜脂突变体，这与化学渗透模型确实存在挑战。相比之下，大肠杆菌的解偶联剂抗性突变体可能会排除解偶联剂，有时仅在相当特定的条件下。还简要考虑了真核和原核系统中的相关现象，以及关于解偶联剂、去偶联剂和某些其他膜活性剂的各种观察结果。
