Hydrodynamic properties of adenosine Ri receptors solubilized from rat cerebral-cortical membranes.
Hydrodynamic properties of adenosine Ri receptors solubilized from rat cerebral-cortical membranes.
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从大鼠大脑皮质膜中溶解的腺苷 Ri 受体的流体动力学特性。
DOI：
10.1042/bj2480635
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Cooper,DM
中科院分区：
文献类型：
--
作者：
Yeung,SM;Perez-Reyes,E;Cooper,DM
腺苷Ri受体和抑制性鸟嘌呤核苷酸调节成分从大鼠大脑皮质膜与胆酸钠溶解。（-）-N6-苯基异丙基[2，8 - 3H]腺苷[（3H] PIA）以高亲和力结合可溶性受体，其保留在膜中观察到的腺苷R1受体的药理学特异性。结合受二价阳离子和鸟嘌呤核苷酸调节。二价阳离子通过增加受体的亲和力和表观数量来增加[3H] PIA结合。鸟嘌呤核苷酸通过增加配体-受体复合物的解离来减少激动剂结合。腺苷激动剂稳定可溶性受体的高亲和力形式。腺苷受体的流体动力学特性测定与胆酸盐提取物的膜，用[3H] PIA处理。蔗糖梯度离心分析表明，该受体的沉降系数为7.7S。受体从Sepharose 6B柱洗脱，表观Stokes半径为7.2 nm。用百日咳毒素和[32 P]-NAD+标记蔗糖梯度或凝胶过滤柱组分揭示了41，000-和39，000-Mr底物与受体活性重叠。这些研究表明，高亲和力的腺苷受体结合活性的胆酸盐提取物代表了一个稳定的R1-N复合物。
Adenosine Ri receptors and inhibitory guanine-nucleotide-regulatory components were solubilized from rat cerebral-cortical membranes with sodium cholate. (-)-N6-Phenylisopropyl[2,8-3H]adenosine [(3H]PIA) binds with high affinity to the soluble receptors, which retain the pharmacological specificity of adenosine Ri receptors observed in membranes. The binding is regulated by bivalent cations and guanine nucleotides. Bivalent cations increase [3H]PIA binding by increasing both the affinity and the apparent number of receptors. Guanine nucleotides decrease agonist binding by increasing the dissociation of the ligand-receptor complex. Adenosine agonists stabilize the high-affinity form of the soluble receptor. The hydrodynamic properties of the adenosine receptor were determined with cholate extracts of membranes that were treated with [3H]PIA. Sucrose-gradient-centrifugation analysis indicates that the receptor has a sedimentation coefficient of 7.7 S. The receptor is eluted from Sepharose 6B columns with an apparent Stokes radius of 7.2 nm. Labelling of either sucrose-gradient or gel-filtration-column fractions with pertussis toxin and [32P]-NAD+ reveals that both the 41,000- and 39,000-Mr substrates overlap with the receptor activity. These studies suggest that the high-affinity adenosine-receptor-binding activity in the cholate extract represents a stable R1-N complex.