Change in surface charge density and membrane potential of intact mitochondria during energization

Kamo, Naoki; Muratsugu, Makoto; Kurihara, Kenzo; Kobatake, Yonosuke

doi:10.1016/0014-5793(76)80979-9

Cited by 44 publications

(27 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The values of A (p shown in Fig. 3 are approximately equal to those obtained previously with the DDA § [18]. In addition, the values obtained here are compatible with those obtained by previous investigators.…”

Section: C~ [L-exp[-~pi~7+exp(fa(p/rt)tt]]supporting

confidence: 93%

“…This method has advantages in that the electrode enables us to monitor the change in membrane potential of such small cells or vesicles easily and continuously. The membrane potential of mitochondria was estimated by use of the DDA+-electrode [18]. However, DDA § required the presence of a lipid-soluble anion such as tetraphenyl boron (TPB-) for permeation through the membrane, and the role of the anion was not made clear [14].…”

Section: Rt C E a = Tf Ln C-mentioning

confidence: 99%

See 1 more Smart Citation

Membrane potential of mitochondria measured with an electrode sensitive to tetraphenyl phosphonium and relationship between proton electrochemical potential and phosphorylation potential in steady state

et al. 1979

Self Cite

View full text Add to dashboard Cite

The membrane potential of mitochondria was estimated from the accumulation of tetraphenyl phosphonium (TPP+), which was determined with the TPP+-selective electrode developed in the present study. The preparation and some operational parameters of the electrode were described. The kinetics for uptake by mitochondria of TPP+ and DDA+ (dibenzyldimethyl ammonium) were analyzed, and it was found that TPP+ permeated the mitochondrial membrane about 15 times faster than DDA+. The final amounts of accumulation of TPP+ and DDA+ by mitochondria were approximately equal. For the state-4 mitochondria, the membrane potential was about 180 mV (interior negative). Simultaneous measurements of TPP+-uptake and oxygen consumption showed that the transition between states 3 and 4 was detectable by use of the TPP+-electrode. After the TPP+-electrode showed that state-4 was reached, the extra-mitochondrial phosphorylation potential was measured. The difference in pH across the membrane was measured from the distribution of permeant anion, acetate, so as to calculate the proton electrochemical potential. The ratio of extra-mitochondrial phosphorylation potential to proton electro-chemical potential, n was close to 3. This value of n was also found to be 3 when ATP was hydrolyzed under the condition that the respiratory chain was arrested. The implication that n = 3 was discussed.

show abstract

Section: C~ [L-exp[-~pi~7+exp(fa(p/rt)tt]]supporting

confidence: 93%

Section: Rt C E a = Tf Ln C-mentioning

confidence: 99%

Membrane potential of mitochondria measured with an electrode sensitive to tetraphenyl phosphonium and relationship between proton electrochemical potential and phosphorylation potential in steady state

et al. 1979

Self Cite

View full text Add to dashboard Cite

show abstract

“…Other reports (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) have described proton movements in restricted domains or in isolated open membrane sheets not capable of sustaining a transmembrane pH gradient (which nevertheless can be energized, ostensibly by generation of an electrochemical H+ gradient for ATP synthesis) or have demonstrated that the pH may not account for the activities attributed to membrane "energization." Taken together, the observations suggest that there may be specific proton-conducting pathways in or on such energy-transducing membranes that allow them to carry out energy transduction without necessarily involving a pH gradient across the membrane.…”

mentioning

confidence: 99%

Anionic lipid headgroups as a proton-conducting pathway along the surface of membranes: a hypothesis.

Haines¹

1983

Proc. Natl. Acad. Sci. U.S.A.

217

167

View full text Add to dashboard Cite

Evidence has been gathering from several laboratories that protons in proton-pumping membranes move along or within the bilayer rather than exchange with the bulk phase. These experiments are typically conducted on the natural membrane in vivo or in vitro or on fragments of natural membrane. Anionic lipids are present in all proton-pumping membranes. Model studies on the protonation state of the fatty acids of liposomes containing entrapped water show that the bilayers always contain mixtures of protonated and deprotonated carboxylates. Protonated fatty acids form stable acid-anion pairs with deprotonatedfatty acids through unusually strong hydrogen bonds. Such acid-anion dimers have a single negative charge, which is shared by the four negative oxygens of both headgroups. The two pK values of the resulting dimer will be significantly different from the pK of the monomeric species, so that the dimer will be stable over a wide pH range. It is proposed that anionic lipid headgroups in biological membranes share protons as acid-anion dimers and that anionic lipids thus trap and conduct protons along the headgroup domain of bilayers that contain such anionic lipids-. Protons pumped from the other side ofthe membrane may enter and move within the headgroup sheet because the protonation rate of negatively charged proton acceptors is 5 orders of magnitude faster than that of water. Protons trapped in the acidic headgroup sheet need not leave this region in order to be utilized by a responsive proton-translocating pore (a transport protein using the proton gradient). Experiments suggest the proton concentration in the headgroup domain may vary widely and the anionic lipid headgroup sheet may therefore function as a proton buffer. -Due to the Gouy-Chapman-Stern layer at polyanionic surfaces, anionic lipids will also sequester protons from the bulk solution at low and moderate ionic strengths. At high ionic strength metal cations may replace protons sequestered near the headgroups, but these cations cannot substitute for protons in the "proton-conducting pathway," which is based on hydrogen bonding.Recent experiments in several laboratories have suggested that protons that are translocated by proton-pumping membranes, such as those of mitochondria and halobacteria, need not enter the external bulk water phase in order to be utilized by protontransporting proteins ofthe membrane, such as ATP synthetase. Notable among these experiments are -those of Michel and Oesterhelt (1), who made careful measurements of proton-dependent ATP synthesis and pH changes in and near illuminated, Halobacterium halobium cells. They found, that the pH is not lowered in the bulk aqueous phase as the protons pumped.by the purple patches of bacteriorhodopsin are utilized by ATP synthetase, which is not present in the purple patches but is found at some distance in red patches ofthe same plasma membrane. They concluded that.the protons do not pass through the bulk aqueous phase but move very close to the membrane surface. This system is un...

show abstract

“…The changes in zeta potential at the outer membrane of mitochondria must be a consequence of energization that occurs at the inner membrane, since the energization of mitochondria is known to occur at the inner membrane. This similar fact was pointed out by Kamo et al (1976) and Shimbo et al (1978) by comparing the zeta potential of mitochondria with the membrane potential determined from the distribution of lipid-soluble cations, e.g., dibenzyl dimethyl ammonium (DDA+). How is the density of fixed charges at the outer membrane surface altered by the energization occurring in the inner membrane?…”

Section: Interaction Of MC With Mitochondriamentioning

confidence: 76%

“…The concentration of mitochondrial protein was 0.4 mg/ml. The buffer contained 10 mM potassium phosphate (pH 7.4), 1 mM MgC12, 0.2 mM EDTA, 250 mM sucrose, 1 /zM rotenone, and 1.5 /zM MC ATP or succinate as described previously (Kamo et al, 1976;Aiuchi et al, 1977).…”

Section: Interaction Of MC With Mitochondriamentioning

confidence: 99%

Electrostatic interaction between merocyanine 540 and liposomal and mitochondrial membranes

Aiuchi

Kobatake

1979

J. Membrain Biol.

Self Cite

View full text Add to dashboard Cite

The fluorescence of merocyanine 540 (MC) in liposomal and mitochondrial suspensions was measured under various conditions. Under a given condition, both the amount of dye bound to the membrane and the zeta potential were determined simultaneously. It was found that the fluorescence intensity was proportional to the amount of bound dye and correlated with the zeta potential of particles. The fluorescence intensity was represented quantiatively in terms of the Langmuir adsorption isotherm, when the electrostatic interaction acting between MC and membrane surface was properly taken into account. It was concluded that the changes in MC fluorescence in the liposomal and mitochondrial suspensions are mainly attributed to the changes in the surface potential of the membranes.

show abstract

Change in surface charge density and membrane potential of intact mitochondria during energization

Cited by 44 publications

References 13 publications

Membrane potential of mitochondria measured with an electrode sensitive to tetraphenyl phosphonium and relationship between proton electrochemical potential and phosphorylation potential in steady state

Membrane potential of mitochondria measured with an electrode sensitive to tetraphenyl phosphonium and relationship between proton electrochemical potential and phosphorylation potential in steady state

Anionic lipid headgroups as a proton-conducting pathway along the surface of membranes: a hypothesis.

Electrostatic interaction between merocyanine 540 and liposomal and mitochondrial membranes

Contact Info

Product

Resources

About