[Membrane-bound acetylcholine receptor from the optical ganglia of the squid Berryteuthis magister].
A procedure of isolation of membrane-bound acetylcholine receptor from the optical ganglia of the squid Berryteuthis magister has been developed. The method described entails tissue disruption by homogenization and ultrasonication, resulting in a crude membrane fraction, and a subsequent washing of the membranes with 1 M NaCl and 0,6 M KCl, reaching the receptor yield of 250 pM per 1 g of tissue. Some properties of the receptor, which is of nicotinic type, were studied. The Kd values for the receptor complexes with acetylcholine (3 +/- 0,5 mkM), nicotine (1 +/- 0,2 mkM), tubocurarine (0,3 +/- 0,1; 4,4 +/- 0,5 mkM), cytisine (0,5 +/- 0,1 mkM), etc. were determined. The binding depends on pH and decreases with a decrease of pH, is inhibited by high concentrations of NaCl and weakly depends on the concentrations of Ca2+, Mg2+ and EDTA sodium salt. In contrast to the acetylcholine receptor of vertebrates, the receptor from the optical ganglia of B. magister is not blocked by decamethonium and alpha-neurotoxin II from the Middle Asian cobra N. naja oxiana venom, a close analog of alpha-bungarotoxin.
D000818:Animals; D001667:Binding, Competitive; D002413:Cations, Divalent; D002462:Cell Membrane / Q000378:metabolism; D049832:Decapodiformes; D005724:Ganglia / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D011950:Receptors, Cholinergic / Q000378:metabolism*
D002413:Cations, Divalent; D011950:Receptors, Cholinergic
Svoĭstva membranosviazannogo atsetilkholinovogo retseptora iz zritel'mykh gangliev kal'mara Berryteuthis magister.