Different effects of N-ethylmaleimide on M1 and M2 muscarine receptors in rat brain.
Different effects of N-ethylmaleimide on M1 and M2 muscarine receptors in rat brain.
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N-乙基马来酰亚胺对大鼠脑中M1和M2毒蕈碱受体的不同影响。
DOI：
10.1073/pnas.82.2.580
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发表时间：
1985
影响因子：
11.1
通讯作者：
Potter,LT
中科院分区：
文献类型：
--
作者：
Flynn,DD;Potter,LT
N-乙基马来酰亚胺（MalNEt）披露了大鼠脑干膜中的M2毒蕈碱受体与海马中的M1受体之间的三个差异。在0.1 mM时，MalNEt完全将M2受体对卡巴胆碱的较高亲和力状态相互转化为较低亲和力状态，而对M1的两种亲和力状态没有影响。这种“解偶联”效应类似于鸟嘌呤核苷酸产生的效应，似乎是由于激动剂-受体复合物与鸟嘌呤核苷酸结合蛋白的分离。较高的MalNEt浓度（1-5 mM）增加了未偶联的M2受体的亲和力，同样对M1状态没有影响。最后，在MalNEt中，M2受体对卡巴胆碱的亲和力与M1受体的亲和力不同。因此，MalNEt是区分M1和M2受体以及M2受体的两种状态的优异试剂。MalNEt对拮抗剂哌仑西平的亲和力或M1-选择性没有影响。
N-Ethylmaleimide (MalNEt) disclosed three differences between M2 muscarine receptors in membranes from the rat brainstem and M1 receptors in the hippocampus. At 0.1 mM, MalNEt completely interconverted the higher affinity state of M2 receptors for carbachol to a lower affinity state, while having no effect on the two affinity states of M1. This "uncoupling" effect is similar to that produced by guanine nucleotides and appears to be due to separation of an agonist-receptor complex from a guanine nucleotide-binding protein. Higher MalNEt concentrations (1-5 mM) increased the affinity of uncoupled M2 receptors, again without effect on M1 states. Finally, in MalNEt, the affinity of M2 receptors for carbachol was different from values for M1 receptors. Thus, MalNEt is an excellent agent for distinguishing M1 and M2 receptors and the two states of M2 receptors. MalNEt had no effect on the affinity or M1-selectivity of the antagonist pirenzepine.