関: protonophoric

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/08/07 21:27:54」(JST)

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A protonophore, also known as a proton translocator, is an ionophore that allows protons to cross lipid bilayers. This would otherwise not occur as protons have positive charge and hydrophilic properties, making them unable to cross without a channel or transporter. Protonophores are generally aromatic compounds that are both hydrophobic and capable of distributing the negative charge over a number of atoms by π-orbitals which delocalize a proton's charge in the molecule.^[1]^[2] Both the neutral and the charged species can diffuse across the lipid bilayer by passive diffusion and simultaneously facilitating proton transport.^[3]

Representative protonophores include:

2,4-dinitrophenol
Carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP)
Carbonyl cyanide m-chlorophenyl hydrazone (CCCP)

Mechanism of action

The facilitated transport of protons across the biological membrane by protonophore is achieved as follows.^[4]

The anionic form of the protonophore (P⁻) is adsorbed onto one side (Positive) of the biological membrane.
Protons (H⁺) from the aqueous solution combine with the anion (P⁻) to produce the neutral from (PH)
PH diffuses across the biological membrane and dissociates into H⁺ and P⁻ on the other side.
This H⁺ is released from the biological membrane into the other aqueous solution
P⁻ returns to the first side of the biological membrane by electrophoresis (its electrostatic attraction to the positive side of the membrane).

References

^ http://biom.3322.org:2966/ebook1/biophy/Fundamental%20Principles%20of%20Membrane%20Biophysics.pdf (accessed 19th Nov 2008)
^ Nicholls, David G., and Ferguson, Stuart J. (2002). "Bioenergetics 3". Academic Press, London. ISBN 0-12-518121-3.
^ Chopineaux-Courtois V, Reymond F, Bouchard G,Carrupt PA, Testa B, Girault HH. (February 1999). "Effects of Charge and Intramolecular Structure on the Lipophilicity of Nitrophenols". J. Am. Chem. Soc. 121 (8): 1743–1747. doi:10.1021/ja9836139.
^ Ozaki S, Kano K, Shirai O (August 2008). "Electrochemical elucidation on the mechanism of uncoupling caused by hydrophobic weak acids". Phys Chem Chem Phys 10 (30): 4449–55. doi:10.1039/b803458c. PMID 18654685.

English Journal

Vectorization of agrochemicals: amino acid carriers are more efficient than sugar carriers to translocate phenylpyrrole conjugates in the Ricinus system.

Wu H1,2, Marhadour S1, Lei ZW3, Yang W3, Marivingt-Mounir C1, Bonnemain JL2, Chollet JF4.
Environmental science and pollution research international.Environ Sci Pollut Res Int.2016 Dec 13. [Epub ahead of print]
Producing quality food in sufficient quantity while using less agrochemical inputs will be one of the great challenges of the twenty-first century. One way of achieving this goal is to greatly reduce the doses of plant protection compounds by improving the targeting of pests to eradicate. Therefore,
PMID 27966081

Targeted mitochondrial uncoupling beyond UCP1 - The fine line between death and metabolic health.

Ost M1, Keipert S2, Klaus S3.
Biochimie.Biochimie.2016 Dec 2. pii: S0300-9084(16)30198-5. doi: 10.1016/j.biochi.2016.11.013. [Epub ahead of print]
In the early 1930s, the chemical uncoupling agent 2,4-dinitrophenol (DNP) was promoted for the very first time as a powerful and effective weight loss pill but quickly withdrawn from the market due to its lack of tissue-selectivity with resulting dangerous side effects, including hyperthermia and de
PMID 27916644

Involvement of mitochondrial permeability transition pore (mPTP) in cardiac arrhythmias: Evidence from cyclophilin D knockout mice.

Gordan R1, Fefelova N1, Gwathmey JK1, Xie LH2.
Cell calcium.Cell Calcium.2016 Dec;60(6):363-372. doi: 10.1016/j.ceca.2016.09.001. Epub 2016 Sep 2.
In the present study, we have used a genetic mouse model that lacks cyclophilin D (CypD KO) to assess the cardioprotective effect of mitochondrial permeability transition pore (mPTP) inhibition on Ca2+ waves and Ca2+ alternans at the single cell level, and cardiac arrhythmias in whole-heart preparat
PMID 27616659

Japanese Journal

Membrane Protein Rim21 Plays a Central Role in Sensing Ambient pH in Saccharomyces cerevisiae

Obara Keisuke,Yamamoto Hayashi,Kihara Akio
Journal of Biological Chemistry 287(46), 38473-38481, 2012-11-09
… Even without external alkalization, the Rim101 pathway was activated in a Rim21-dependent manner by either protonophore treatment or depletion of phosphatidylserine in the inner leaflet of the plasma membrane, both of which caused plasma membrane depolarization like the external alkalization. …
NAID 120005090608

ATP-Dependent but Proton Gradient-Independent Polyphosphate-Synthesizing Activity in Extraradical Hyphae of an Arbuscular Mycorrhizal Fungus

Tani Chiharu,Ohtomo Ryo,Osaki Mitsuru,Kuga Yukari,Ezawa Tatsuhiro
Applied and Environmental Microbiology 75(22), 7044-7050, 2009-11
… This activity was inhibited by vanadate but not by bafilomycin A1 or a protonophore, suggesting that ATP may not energize the reaction through H+-ATPase but act as a direct substrate in the reaction. …
NAID 120002087036

Involvement of OCTN1 (SLC22A4) in pH-dependent transport of organic cations

Tamai Ikumi,Nakanishi Takeo,Kobayashi Disuke,China Kayoko,Kosugi Yohei,Nezu Jun-ichi,Sai Yoshimichi,Tsuji Akira
Molecular Pharmaceutics 1(1), 57-66, 2004-01
… A protonophore and membrane potential affected the overshoot uptake. …
NAID 120001893515