Synthetic localization of a second toxin-binding region within residues. cap alpha. 182-198 of Torpedo acetylcholine receptor
A peptide, corresponding to the region 182-198 (peptide ..cap alpha..T182-198) of the ..cap alpha.. chain of Torpedo californica acetylcholine (AChR) was synthesized, purified and characterized. The binding activities of this peptide to ..cap alpha..-bungarotoxin and to cobratoxin were studied and compared to the activities of the previously reported synthetic peptide ..cap alpha..T125-147 of Torpedo ..cap alpha.. chain. Binding studies were performed by quantitative radiometric titrations by studying the binding of /sup 125/I-labelled peptides to toxin adsorbents and the binding of /sup 125/I labelled toxins to peptide adsorbents. The specificity of the binding was confirmed by appropriate inhibition experiments. The results showed unequivocally that the ..cap alpha.. chain of AChR contains a second toxin binding region which resides within, but may not comprise all of, the residues 182-198. The binding of toxins to one synthetic region is inhibited by the other. Thus, the ..cap alpha.. chain of AChR contains at least two toxin binding regions which may either be two faces of a larger single binding site or, alternatively, two binding sites that are spatially very close and thus the binding of one synthetic region to the toxin site could sterically obstruct the binding of the second synthetic region.
- Research Organization:
- Baylor College of Medicine, Houston, TX
- OSTI ID:
- 7024764
- Report Number(s):
- CONF-8604222-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:4; ISSN FEPRA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
AMINES
AMMONIUM COMPOUNDS
ANIMALS
ANTIGENS
AQUATIC ORGANISMS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL LOCALIZATION
COMPARATIVE EVALUATIONS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ESTERS
FISHES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MATERIALS
MEMBRANE PROTEINS
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PARASYMPATHOMIMETICS
PEPTIDES
PROTEINS
PURIFICATION
QUATERNARY COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
VERTEBRATES