Non-competitive antagonist

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Example of a non-competitive inhibition of the effects of an agonist

In pharmacology and biochemistry, a non-competitive antagonist is a substance that is able to inhibit the binding of an agonist to a receptor without this substance being able to be displaced by the agonist. Non-competitive antagonists can bind to a different ( allosteric ) binding site than the agonist to the receptor. Signal transmission inhibitors also behave like non-competitive antagonists. Substances that bind irreversibly to the receptor can also show a non-competitive antagonism.

One example is the active ingredient ketamine (which is not called a non-competitive antagonist but an uncompetitive antagonist in the English literature ) , which does not block the binding site for the physiological agonist glutamate on the NMDA receptor , but the canal pore itself (but only after - hence the different classification - the agonist glutamate had opened it by itself). Dose-effect curves and the position of the EC 50 change accordingly.

See also

literature

  • Jeremy M. Berg, John L. Tymoczko, Lubert Stryer : Biochemistry. 6 edition, Spektrum Akademischer Verlag, Heidelberg 2007. ISBN 978-3-8274-1800-5 .
  • Donald Voet, Judith G. Voet: Biochemistry. 3rd edition, John Wiley & Sons, New York 2004. ISBN 0-471-19350-X .
  • Bruce Alberts , Alexander Johnson, Peter Walter, Julian Lewis, Martin Raff, Keith Roberts: Molecular Biology of the Cell , 5th Edition, Taylor & Francis 2007, ISBN 978-0815341062 .
  • Forth, Henschler, Rummel: General and special pharmacology and toxicology , Munich, 2001.