Specific binding of [3H]+/- 2-amino-7-phosphono heptanoic acid to rat brain membranes in vitro.
Specific binding of [3H]+/- 2-amino-7-phosphono heptanoic acid to rat brain membranes in vitro.
复制标题
[ 3 H] /-2-氨基-7-膦酰基庚酸与大鼠脑膜的体外特异性结合。
DOI：
10.1016/0024-3205(83)90011-5
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发表时间：
1983
期刊：
影响因子：
6.1
通讯作者：
Coyle,JT
中科院分区：
文献类型：
--
作者：
Ferkany,JW;Coyle,JT
[3 H]±2-氨基-7-膦酰基庚酸（3 H-APH）是一种N-甲基-D-天冬氨酸（NMDA）的强抑制剂，它与大鼠脑线粒体粗品的特异性结合。结合在生理pH和温度下是最佳的，并且在三柠檬酸盐缓冲液中，在60分钟内达到平衡。前脑平衡数据的Scatchard分析揭示了单一的非相互作用的结合位点群体（B Mapp= 15皮摩尔/mg蛋白; K Dapp= 3.6 μ M; Hill系数= 0.92，r= 0.99; N= 5）。配体的特异性结合很容易被未标记的APH逆转，并且在外周组织（包括心脏、肺、肾、肝、脾和横纹肌）和热处理的脑超声处理物中不存在。从不同区域制备的与脑膜结合的配体的量的8倍变化被观察到，在海马结构中结合最大，在中脑中结合最少。红藻氨酸、NMDA和天冬氨酸对[3 H]-APH位点的亲和力可忽略不计;相反，使君子酸、鹅膏蕈氨酸、谷氨酸、同型半胱氨酸和2-氨基-4-膦酰基丁酸是中等有效的置换剂。结果表明，[3 H]-APH在体外标记了一个使君子酸偏好位点.然而，与[3 H]-谷氨酸标记的受体不同，[3 H]-AHP结合在氯离子存在下减弱，表明该配体可能标记兴奋性氨基酸受体的亚群。
The specific binding of [3 H]±2-amino-7-phosphono heptanoic acid (3 H-APH), a potent N-methyl-D-aspartate (NMDA) antagpnist, to extensively washed, previously frozen crude mitochondrial fractions of rat brain is described. Binding was optimal at physiological pH and temperature and, in Triscitrate buffer, attained equilibrium within 60 minutes. Scatchard analysis of the equilibrium data for forebrain revealed a single, non-interacting population of binding sites (B Mapp= 15 picomoles/mg protein; K Dapp= 3.6 uM; Hill coefficient= 0.92, r= 0.99; N= 5). Specific binding of the ligand was readily reversible by unlabeled APH and was absent in peripheral tissues including heart, lung, kidney, liver, spleen and striate muscle and in heat treated brain sonicates. An 8-fold variation in the amount of ligand bound to brain membranes prepared from different regions was observed with binding being greatest in the hippocampal formation and least in the midbrain. Kainic acid, NMDA and aspartic acid exhibited negligible affinity for the [3 H]-APH site; in contrast, quisqualic acid, ibotenic acid, glutamatic acid, homocysteic acid and 2-amino-4-phosphono butyric acid were moderately potent displacers. The results indicate that [3 H]-APH labels a quisqualate preferring site in bvitro. Unlike the receptor labeled by [3 H]-glutamate however,[3 H]-AHP binding was attenuated in the presence of chloride ions suggesting that this ligand may label a subpopulation of excitatory amino acid receptors.