Ionophore A23187: the effect of H+ concentration on complex formation with divalent and monovalent cations and the demonstration of K+ transport in mitochondria mediated by A23187

D R Pfeiffer, H A Lardy


The two-phase extraction technique has been used to study the equilibrium between A23187, metal cations, and H+. Under these conditions the ionophore forms charge neutral isostoichiometric complexes with divalent cations in which both carboxylate groups of the 2:1 A23187:M2+ complexes are deprotonated. In ethanol, however, the methyl ester of A23187 also binds divalent cations indicating that protonated complexes between A23187 and cations should also exist. With monovalent cations, A23187 forms two charge-neutral complexes of stoichiometries and relative stabilities: A2HM greater than AM. Examination of energy utilization K+ and H+ movements, and light scattering capacity of mitochondria in the presence of divalent cation chelators, A23187, and valinomycin demonstrates that A23187 can act as a nigericin type K+ ionophore under appropriate conditions. Formation constants for the A2HM complexes with monovalent cations indicate that with appropriate conditions transport of Li+ and Na+ mediated by A23187 would also be expected. The binding constant data and associated free energies of complex formation are compared as a function of ionic radius and of cation charge. The data indicate that lack of conformational mobility in A23187 ...Continue Reading


Apr 21, 1975·Biochimica Et Biophysica Acta·A HyonoS L Bonting
Jan 1, 1974·Proceedings of the National Academy of Sciences of the United States of America·Z SelingerM Schramm
Nov 1, 1967·Proceedings of the National Academy of Sciences of the United States of America·B C PressmanJ H Johnson
Mar 20, 1974·Journal of the American Chemical Society·M O ChaneyJ L Occolowitz
Jan 1, 1971·Annual Review of Microbiology·P J Henderson
Oct 6, 1972·Biochemical and Biophysical Research Communications·A H Caswell, B C Pressman
Oct 31, 1969·Annals of the New York Academy of Sciences·B C Pressman


Jan 1, 1979·Planta·T H Chen, L F Jaffe
Dec 1, 1987·Archives of Toxicology·L Pezzi, W Y Cheung
Aug 1, 1980·Journal of Bioenergetics and Biomembranes·G Y ShiG P Brierley
Jan 1, 1989·Neurochemical Research·R A PhilibertG R Dutton
Mar 8, 1977·The Journal of Membrane Biology·E F LaBelle, E Racker
Aug 15, 1977·Experientia·W J MalaisseG Somers
Oct 15, 1982·Experientia·K S Pyant, G P Brierley
Jul 1, 1991·The Journal of Membrane Biology·T J Simons
Jan 1, 1981·Archives of Biochemistry and Biophysics·J S PuskinM T Coene
Sep 19, 1977·Biochimica Et Biophysica Acta·S P Young, B D Gomperts
Jun 11, 1990·Biochimica Et Biophysica Acta·J A Veiro, P R Cullis
Aug 1, 1980·Cellular Immunology·J D JohnsonN L King-Thompson
Jan 1, 1986·Biochimica Et Biophysica Acta·K D Garlid, A D Beavis
Feb 1, 1977·Proceedings of the National Academy of Sciences of the United States of America·N Kaiser, I S Edelman
Aug 1, 1978·Proceedings of the National Academy of Sciences of the United States of America·J MoranJ A Fischer
Mar 1, 1980·Proceedings of the National Academy of Sciences of the United States of America·G WeissmannE Goodman
Jan 1, 1981·Proceedings of the National Academy of Sciences of the United States of America·M DeleersW J Malaisse
May 1, 1982·Proceedings of the National Academy of Sciences of the United States of America·R BrasseurJ M Ruysschaert
Jun 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·R Brasseur, M Deleers
Jan 22, 2010·The Journal of Biological Chemistry·Florentina PenaIneke Braakman
Feb 1, 1978·The Journal of Cell Biology·J C GilkeyG T Reynolds
Sep 1, 1987·The Journal of Experimental Medicine·H Takayama, M V Sitkovsky
Feb 1, 1987·The Journal of General Physiology·G D NicolM D Bownds
Mar 1, 1987·The Journal of General Physiology·P P Schnetkamp, M D Bownds
Dec 1, 1979·Antimicrobial Agents and Chemotherapy·B J AbbottL Farhner
Dec 1, 1976·The Journal of Clinical Investigation·J L IveyA H Tashjian
Aug 17, 1978·Biochimica Et Biophysica Acta·M Hershkowitz
Jan 1, 1993·Critical Reviews in Microbiology·J Youatt
Aug 18, 2004·Archives of Biochemistry and Biophysics·Majidreza KamyarRosa Lemmens-Gruber
Mar 17, 1977·Biochimica Et Biophysica Acta·J Wulf, W G Pohl
Jan 15, 1983·Thrombosis Research·B Lages, C Kruger
Jun 1, 1985·Cell Calcium·T R Hinds, F F Vincenzi
May 1, 1982·Cell Calcium·U B Kaupp, P P Schnetkamp
May 1, 1984·British Journal of Pharmacology·E J BarbieriR F McMichael
Jan 24, 1977·Biochemical and Biophysical Research Communications·J Duszyński, L Wojtczak
Jul 1, 1980·Archives of Biochemistry and Biophysics·G Ben-Hayyim, G H Krause
Jan 8, 1981·Biochimica Et Biophysica Acta·J T O'FlahertyC E McCall
Mar 2, 1999·Archives of Biochemistry and Biophysics·J WudarczykE Lenartowicz
May 17, 1977·Biochemistry·T C Wun, R Bittman
Nov 23, 1982·Biochemistry·J R White, F L Pearce
Jan 29, 1985·Biochemistry·P P Schnetkamp, U B Kaupp
Aug 11, 1987·Biochemistry·M B SankaramK R Easwaran
Sep 3, 1991·Biochemistry·P ZimniakR Lester
Jan 5, 2000·Physiological Reviews·D G Nicholls, S L Budd

Related Concepts

Bacteriocidal Agents
Cations, Divalent
Cations, Monovalent
Hydrogen-Ion Concentration
Mitochondria, Liver

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

The Tendon Seed Network

Tendons are rich in the extracellular matrix and are abundant throughout the body providing essential roles including structure and mobility. The transcriptome of tendons is being compiled to understand the micro-anatomical functioning of tendons. Discover the latest research pertaining to the Tendon Seed Network here.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.


Incretins are metabolic hormones that stimulate a decrease in glucose levels in the blood and they have been implicated in glycemic regulation in the remission phase of type 1 diabetes. Here is the latest research.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Long COVID-19

“Long Covid-19” describes illness in patients who are reporting long-lasting effects of the SARS-CoV-19 infection, often long after they have recovered from acute Covid-19. Ongoing health issues often reported include low exercise tolerance and breathing difficulties, chronic tiredness, and mental health problems such as post-traumatic stress disorder and depression. This feed follows the latest research into Long Covid.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.