Dopamine D2 receptor dimer formation -: Evidence from ligand binding
Dopamine D2 receptor dimer formation -: Evidence from ligand binding
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DOI：
10.1074/jbc.m006936200
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发表时间：
2001-06-22
影响因子：
4.8
通讯作者：
Strange, PG
中科院分区：
文献类型：
--
作者：
Armstrong, D;Strange, PG
我们已经检查了在中国仓鼠卵巢细胞中表达的两个放射线（[H-3]尖龙和[sh] raclopride）与D-2多巴胺受体的结合。在钠离子存在的饱和结合实验中，两个放射性物体都标记了相似数量的位点，而在没有钠离子[H-3] raclopride的情况下，标记为[H-3]尖龙标记的位点数量的一半。然而，在没有钠离子的情况下，在没有钠离子的情况下，raclopride能够完全抑制[H-3]尖龙的结合。在没有[H-3]尖龙的饱和分析中，在没有钠离子raclopride的情况下发挥了非竞争作用，减少了放射性物体标记的地点数量。这些数据是用一个模型来解释的，其中受体存在为二聚体，在没有钠离子的情况下，raclopride在整个二聚体之间发挥负合作性，既可以自身结合和尖刺的结合。已经产生了一种受体模型，可很好地描述此处描述的实验现象。
We have examined the binding of two radioligands ([H-3]spiperone and [SH]raclopride) to D-2 dopamine receptors expressed in Chinese hamster ovary cells. In saturation binding experiments in the presence of sodium ions, both radioligands labeled a similar number of sites, whereas in the absence of sodium ions [H-3]raclopride labeled about half the number of sites labeled by [H-3]spiperone. In competition experiments in the absence of sodium ions, however, raclopride was able to inhibit [H-3]spiperone binding fully. In saturation analyses with [H-3]spiperone in the absence of sodium ions raclopride exerted noncompetitive effects, decreasing the number of sites labeled by the radioligand. These data are interpreted in terms of a model where the receptor exists as a dimer, and in the absence of sodium ions, raclopride exerts negative cooperativity across the dimer both for its own binding and the binding of spiperone. A model of the receptor has been produced that provides a good description of the experimental phenomena described here.