Human bradykinin B2 receptors isolated by receptor-specific monoclonal antibodies are tyrosine phosphorylated.
Human bradykinin B2 receptors isolated by receptor-specific monoclonal antibodies are tyrosine phosphorylated.
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通过受体特异性单克隆抗体分离的人缓激肽 B2 受体是酪氨酸磷酸化的。
DOI：
10.1073/pnas.90.23.10994
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发表时间：
1993
影响因子：
11.1
通讯作者：
Baenziger,NL
中科院分区：
文献类型：
--
作者：
Jong,YJ;Dalemar,LR;Wilhelm,B;Baenziger,NL
我们报告的免疫亲和分离缓激肽B2受体的酪氨酸磷酸化状态从WI-38人肺成纤维细胞。我们产生了六个单克隆抗体针对B2缓激肽受体介导的前列腺素E2生产的WI-38的生物活性。这些细胞表达具有密切相关的生物活性和[3 H]缓激肽结合的缓激肽受体亲和形式的库。一些单克隆抗体选择性识别中等亲和力（Kd = 5.6 nM）或低亲和力（Kd = 42 nM）受体形式，而另一些则识别两者共有的表位。单克隆抗体阻断缓激肽结合和生物活性。免疫亲和色谱法对固定化的单克隆抗体的中间加低亲和力特异性产生WI-38 B2受体与完整的[3 H]缓激肽结合活性和分子量为78 kDa。所有单克隆抗体的免疫印迹均显示相同的条带，表明不同亲和力的受体形式具有相似的分子量。抗磷酸酪氨酸抗体证明受体是酪氨酸磷酸化的，对受体功能和调节有影响。染料木黄酮完全抑制缓激肽介导的前列腺素E2的产生，IC 50为8 μ M，表明酪氨酸激酶活性对导致花生四烯酸释放的信号转导至关重要。
We report the immunoaffinity isolation of bradykinin B2 receptors in a tyrosine-phosphorylated state from WI-38 human lung fibroblasts. We generated six monoclonal antibodies directed against B2 bradykinin receptor biologic activity mediating prostaglandin E2 production in WI-38. These cells express a repertoire of bradykinin receptor affinity forms with closely correlated biologic activity and [3H]bradykinin binding. Some of the monoclonal antibodies selectively recognize intermediate-affinity (Kd = 5.6 nM) or low-affinity (Kd = 42 nM) receptor forms, whereas others recognize epitopes common to both. The monoclonal antibodies block bradykinin binding and biologic activity. Immunoaffinity chromatography on an immobilized monoclonal antibody of intermediate- plus low-affinity specificity yields WI-38 B2 receptors with intact [3H]bradykinin binding activity and a molecular mass of 78 kDa. The same band is immunoblotted by all the monoclonal antibodies, indicating a similar molecular mass for receptor forms of different affinity. Anti-phosphotyrosine antibodies demonstrate that the receptors are tyrosine phosphorylated, with implications for receptor function and regulation. Genistein completely inhibits bradykinin-mediated prostaglandin E2 production with an IC50 of 8 microM, indicating that tyrosine kinase activity is critical for the signal transduction leading to arachidonic acid release.