Benzodiazepine binding ste on GABA receptors is on-
Ans. is 'b' i.e., a-subunit o The exact subunit structures of native GABA receptors are still are unknown, but it is thought that most GABA receptor are composed of a, b and g subunits that Coassemble with some uncertain stoichiometryo Binding site of GABA is on b-subunit.o Benzodiazepine site is located on the a subunit but the stabilization or completion of that site in the assembled structure also requires the g subunit."The photo-affinity labelling of the benzodiazepine site has confirmed, using isoform - antibodies, to be on an a and not a g subunit". -- Receptor subunit & complexes.o So, BZD binding site is present on a subunit at a - g interface, and both a & g units are required for BZDs action.o Barbiturates act on picrotoxin site that is located usually on b - subunit at a- b interface. Both a & b subunit are required for barbiturates action.o GABA - b - subunito BZD - a subunit at a - g interface, i.e. a/g siteo Barbiturate - b subunit at a- b interface, i.e. a/b site
g-subunit
a-subunit
b-subunit
d-subunit
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