Acetylcholine-receptor-mediated ion fluxes in Electrophorus electricus and Torpedo California membrane vesicles

1985 ◽  
pp. 73-117 ◽  
Author(s):  
Derek J. Cash ◽  
Hitoshi Aoshima ◽  
Elena B. Pasquale ◽  
George P. Hess
Keyword(s):  
Acetylcholine Receptor ◽  
Membrane Vesicles ◽  
Ion Fluxes ◽  
Electrophorus Electricus

Acetylcholine receptor: evidence for a regulatory binding site in investigations of suberyldicholine-induced transmembrane ion flux in Electrophorus electricus membrane vesicles

Biochemistry ◽  
1983 ◽  
Vol 22 (25) ◽  
pp. 5967-5973 ◽  
Author(s):  
Elena B. Pasquale ◽  
Kunio Takeyasu ◽  
Jayant B. Udgaonkar ◽  
Derek J. Cash ◽  
Matthew C. Severski ◽  
...  
Keyword(s):  
Binding Site ◽  
Acetylcholine Receptor ◽  
Membrane Vesicles ◽  
Ion Flux ◽  
Electrophorus Electricus

Acetylcholine receptor-controlled ion fluxes in membrane vesicles investigated by fast reaction techniques

Nature ◽  
1979 ◽  
Vol 282 (5736) ◽  
pp. 329-331 ◽  
Author(s):  
George P. Hess ◽  
Derek J. Cash ◽  
Hitoshi Aoshima
Keyword(s):  
Acetylcholine Receptor ◽  
Membrane Vesicles ◽  
Ion Fluxes ◽  
Fast Reaction

scholarly journals Chemical Modification of the Active Site of the Acetylcholine Receptor

1969 ◽  
Vol 54 (1) ◽  
pp. 245-264 ◽  
Author(s):  
Arthur Karlin
Keyword(s):  
Chemical Modification ◽  
Acetylcholine Receptor ◽  
Disulfide Bond ◽  
Active Site ◽  
Quaternary Ammonium ◽  
Competitive Inhibitor ◽  
Affinity Labels ◽  
Electrophorus Electricus ◽  
Depolarizing Agents ◽  
Monoquaternary Ammonium

The receptor for acetylcholine in the subsynaptic membrane of the electroplax of Electrophorus electricus is a protein with a disulfide bond in the vicinity of the active site. This disulfide can be reduced and reoxidized with concomitant inhibition and restoration of the response to acetylcholine and other monoquaternary ammonium-depolarizing agents. Conversely, the bisquaternary hexamethonium, normally a competitive inhibitor, causes depolarization, and the activity of decamethonium is increased following reduction of the disulfide. The reduced receptor can be alkylated by various maleimide derivatives and is then no longer reoxidizable. Some quaternary ammonium maleimide derivatives act as affinity labels of the reduced receptor, alkylating it at a rate three orders of magnitude faster then do uncharged maleimide derivatives. Other types of potential affinity labels also react only with the reduced receptor and the resulting covalently attached quaternary ammonium moieties interact with the active site, strongly activating the receptor. These results suggest a model for the active site and its transitions in which an activator such as acetylcholine bridges between a negative subsite and a hydrophobic subsite in the vicinity of the disulfide, causing an altered conformation around the negative subsite and a decrasee of a few angstroms in the distance between the two subsites.

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