Demushkin V P, Khramtsov N V
Biokhimiia. 1981 Apr;46(4):674-80.
A new procedure for isolation of the membrane-bound acetylcholine receptor from cow brain N. caudatus is proposed. The procedure described includes tissue disruption by homogenization and ultrasonication, isolation of a crude membrane fraction and subsequent washing of the membranes with 1 M NaCl and 0,6 M KCl. The receptor yield is 40 nmoles per 1 g of tissue. The receptor is of a muscarine type. The K alpha values for the complexes with acetylcholine (3,8.10(-5) M), D,L-muscarine (3,7.10(-5) M), pilocarpine (3,7.10(-5) M), methylfurmethide (3,7.10(-5) M), atropine (2,5.10(-8) M and 1,2.10(-9) M) and platyphyllin (2,3.10(-7) M) were determined. The atropine binding within the pH range of 5 to 8 is weakly dependent on concentrations of Ca2+, Mg2+ and EDTA and EGTA sodium salts as well as on pH. Atropine binding is inhibited by high concentrations of NaCl. It is concluded that N. caudatus from cow brain is a convenient source for isolation of the muscarine acetylcholine receptor.
提出了一种从牛脑尾状核中分离膜结合型乙酰胆碱受体的新方法。所述方法包括通过匀浆和超声处理破坏组织、分离粗膜部分以及随后用1M氯化钠和0.6M氯化钾洗涤膜。受体产量为每1g组织40纳摩尔。该受体为毒蕈碱型。测定了与乙酰胆碱（3.8×10⁻⁵M）、D,L-毒蕈碱（3.7×10⁻⁵M）、毛果芸香碱（3.7×10⁻⁵M）、甲基呋麦噻（3.7×10⁻⁵M）、阿托品（2.5×10⁻⁸M和1.2×10⁻⁹M）以及阔叶缬草碱（2.3×10⁻⁷M）形成复合物的Kα值。在pH值为5至8的范围内，阿托品结合对Ca²⁺、Mg²⁺以及EDTA和EGTA钠盐的浓度以及pH的依赖性较弱。高浓度的氯化钠会抑制阿托品结合。得出的结论是，牛脑尾状核是分离毒蕈碱型乙酰胆碱受体的便利来源。
