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The ionic channel of the nicotinic acetylcholine receptor is unable to differentiate between the optical antipodes of perhydrohistrionicotoxin
Author(s) -
Spivak C.E.,
Maleque M.A.,
Takahashi K.,
Brossi A.,
Albuquerque E.X.
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80816-3
Subject(s) - chemistry , enantiomer , acetylcholine receptor , biophysics , nicotinic acetylcholine receptor , steric effects , rana , acetylcholine , ionic bonding , receptor , endocrinology , stereochemistry , ion , biology , biochemistry , organic chemistry
The enantiomers of perhydrohistrionicotoxin were studied in their effects on endplate currents recorded at the junctional region of sartorius muscles of Rana pipiens . The two optical antipodes progressively decreased the peak amplitude of the endplate currents and were indistinguishable from each other at all times. The enantiomers shortened equally the time constants for endplate current decay, but did not alter their voltage sensitivities. Although perhydrohistrionicotoxin contains 4 chiral centers, complete steric inversion does not alter its effects on the acetylcholine receptor—ion channel complex. By contrast the recognition site of the AcChR is extremely sensitive to any change in the chirality of agonists.