The Use of Optical Probes to Monitor the Formation of pH Gradients and Membrane Potential in Tonoplast Membrane Vesicles
Concomittant with an increasing interest in the role of ion gradients in energizing and regulating a variety of cellular functions, methods have been developed to monitor these gradients in cells, organelles, and membrane vesicles. Of particular interest are gradients of H+ (ΔpH) which, in association with electric potential gradients (ΔΨ), are of central importance in cellular bioenergetics. Because of this central importance of H+ and electric potential gradients a variety of methods have been developed to specifically monitor the formation and magnitude of ΔpH and Δψ in membrane structures too small to be impaled with microelectrodes. Most methods rely on the use of chemical “probes” which distribute across membranes in response to ΔpH or Δψ and whose distribution can be quantified and correlated with the magnitude of the gradient.
KeywordsPermeability Sucrose Corn Adenosine Vanadate
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- DuPont FM, Bennett AB, Spanswick RM (1982a) Proton transport in membrane vesicles from corn roots. In Marme C, Marre E, Hertel R (eds) Plasmalemma and Tonoplast: Their Functions in the Plant Cell, Elsevier Biomedical Press, Amsterdam, p 409Google Scholar
- Lee, HC, Forte JG, Epel D (1982) The use of fluorescent amines for the measurement of pH1: Applications in liposomes, gastric microsomes, and sea urchin gametes. In Nucitelli R, Deamer DW (eds) Intracellular pH: Its Measurement, Regulation, and Utilization in Cellular Functions, Alan R. Liss, New York, p 136Google Scholar
- Nichols JW, Hill MW, Bangham AD, Deamer DW (1980) Measurement of net proton-hydroxyl permeability of large unilamellar liposomes with the fluorescent pH probe, 9-aminoacridine. Biochim Biophys Acta 596: 383–403Google Scholar
- Schuldiner S, Rottenberg H, Avron M (1972) Determination of ΔpH in chloroplasts. 2. Fluorescent amines as a probe for the determination of ApH in chloroplasts. Eur J Biochem 25: 64–70Google Scholar
- Vara F, Serrano R (1982) Partial purification and properties of the proton-translocating ATPase of plant plasma membranes. J Biol Chem 257: 12826–12830Google Scholar