α-Bungarotoxin interacts with the rat brain tachykinin receptors

• Published in: FEBS letters Vol. 255; no. 1; pp. 111 - 115
• Main Authors: Utkin, Yu.N., Lazakovich, E.M., Kasheverov, I.E., Tsetlin, V.I.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 11-09-1989; Elsevier
• Subjects: AChR, acetylcholine receptor; Aminoacids, peptides. Hormones. Neuropeptides; Analytical, structural and metabolic biochemistry; Animals; BH-EL and BH-SP, eledoisin and substance P modified with Bolton-Hunter reagent; Binding Sites - drug effects; Biological and medical sciences; Brain - metabolism; Bungarotoxins - pharmacology; CHAPS, (3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate; EL, eledoisin; Eledoisin - metabolism; Fundamental and applied biological sciences. Psychology; Proteins; Rat brain membrane; Rats; Receptors, Neurotransmitter - metabolism; Receptors, Tachykinin; Solubility; SP, substance P; Substance P; Substance P - metabolism; Tachykinin receptor; TChR, tachykinin receptor; α-Bungarotoxin; αBgt, α-bungarotoxin; BH-EL and BH-SP, eledoisin and substance P modified with Bolton-Hunter reagent; Substance P; AChR, acetylcholine receptor; TChR, tachykinin receptor; SP, substance P; CHAPS, (3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate; αBgt, α-bungarotoxin; Tachykinin receptor; α-Bungarotoxin; EL, eledoisin; Rat brain membrane; Toxin; Tachykinin; Hormonal receptor
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(89)81071-3

α-Bungarotoxin (αBgt) was shown to inhibit the binding of the
125I-labeled substance P (SP) and eledoisin (EL) to the rat brain membranes with
K
1 values of 8.0±5.0 × 10
−8 and 1.1±0.5 × 10
−6 M, respectively. Lower inhibitory activity was manifested by several other postsynaptically acting snake venom neurotoxins. The αBgt inhibition of SP binding with a
K
1 value of 8.5±5.5 × 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 αBgt-binding polypeptides, distinct from neuronal AChRs, may be functionally associated with the tachykinin receptors (TchR).