Abstract
Both the bee venom toxin, mast cell degranulating peptide (MCD peptide) and the mamba toxin dendrotoxin I are potent central convulsants. The two specific receptor sites for these two types of polypeptide toxins are in allosteric interaction in brain membranes. Occupation of the dendrotoxin I binding site (KI = 0.4 nM) prevents binding of the 125I-MCD peptide to its own receptor (KI = 0.23 nM). This inhibition is of the non-competitive type. Autoradiography has shown that a high enough dendrotoxin I concentration (30 nM) prevented binding of 125I MCD peptide to all brain structures where specific receptors had been identified. A lower concentration of the mamba toxin led to a nearly selective inhibition of MCD peptide binding to the hippocampal region which is responsible for the convulsant properties of the 2 types of polypeptide toxins.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Allosteric Regulation
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Amino Acid Sequence
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Animals
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Bee Venoms / metabolism*
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Brain / metabolism
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Convulsants
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Elapid Venoms / metabolism*
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Elapid Venoms / pharmacology
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Growth Inhibitors*
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Interleukin-6*
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Intracellular Membranes / metabolism
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Ion Channels / metabolism
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Leukemia Inhibitory Factor
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Lymphokines / isolation & purification*
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Lymphokines / physiology
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Neurotoxins / metabolism*
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Peptides / metabolism*
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Peptides / pharmacology
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Potassium / metabolism
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Potassium Channels*
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Rats
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Receptors, Cholinergic / metabolism*
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Receptors, Peptide*
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Synaptosomes / metabolism
Substances
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Bee Venoms
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Convulsants
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Elapid Venoms
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Growth Inhibitors
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Interleukin-6
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Ion Channels
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Leukemia Inhibitory Factor
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Lymphokines
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Neurotoxins
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Peptides
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Potassium Channels
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Receptors, Cholinergic
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Receptors, Peptide
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dendrotoxin receptor
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mast cell degranulating peptide receptor
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mast cell degranulating peptide
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dendrotoxin
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Potassium