alpha-Bungarotoxin interacts with the rat brain tachykinin receptors.
alpha-Bungarotoxin (alpha Bgt) was shown to inhibit the binding of the 125I-labeled substance P (SP) and eledoisin (EL) to the rat brain membranes with Kl values of 8.0 +/- 5.0 x 10(-8) and 1.1 +/- 0.5 x 10(-6) M, respectively. Lower inhibitory activity was manifested by several other postsynaptically acting snake venom neurotoxins. The alpha Bgt inhibition of SP binding with a Kl value of 8.5 +/- 5.5 x 10(-8) M to solubilized preparations of the rat brain membranes was demonstrated. The capacity to displace SP was found for d-tubocurarine and phencyclidine, although at concentrations considerably higher than those affecting the nicotinic acetylcholine receptors (AChRs). The results obtained suggest that some of the alpha Bgt-binding polypeptides, distinct from neuronal AChRs, may be functionally associated with the tachykinin receptors (TchR).
Utkin YuN
Shemyakin Institute of Bioorganic Chemistry, USSR Academy of Sciences, Moscow.
Lazakovich
E M
EM
Kasheverov
I E
IE
Tsetlin
V I
VI
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D002038:Bungarotoxins / Q000494:pharmacology*; D004600:Eledoisin / Q000378:metabolism; D051381:Rats; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D018039:Receptors, Tachykinin; D012995:Solubility; D013373:Substance P / Q000378:metabolism
D002038:Bungarotoxins; D017981:Receptors, Neurotransmitter; D018039:Receptors, Tachykinin; D013373:Substance P; D004600:Eledoisin