Photoaffinity labelling of a thromboxane A2/prostaglandin H2 antagonist binding site in human platelets.
Photoaffinity labelling of a thromboxane A2/prostaglandin H2 antagonist binding site in human platelets.
复制标题
人血小板中血栓素 A2/前列腺素 H2 拮抗剂结合位点的光亲和标记。
DOI：
10.1016/0006-291x(86)91067-3
复制
发表时间：
1986
影响因子：
3.1
通讯作者：
Halushka,PV
中科院分区：
文献类型：
--
作者：
Mais,DE;Burch,RM;OatisJr,JE;Knapp,DR;Halushka,PV
合成了9，11-二甲基亚甲基-11，12-亚甲基-16-（4-氨基苯氧基）-13，14-二氢-13-氮杂-15 αβ-ω-四去甲TXA 2的重氮盐（PTA-POA），并将其作为人血小板TXA 2-PGH 2受体的光亲和配体。用PTA-POA的重氮盐孵育人血小板膜，然后在290 nm（hν）处光解，导致放射性配体结合试验中测定的[125 I] PTA-OH的特异性结合降低40%。与TXA 2 PGH 2激动剂共孵育，然后光解，特异性结合没有减少。将PTA-POA的重氮盐与溶解的血小板膜一起温育而不进行光解，随后进行Scatchard分析，结果是[125 I] PTA-OH（38 nM）和与重氮盐温育的制剂（42 nM）的Kd没有变化。然而，[125 I] PTA-OH结合的B max从对照的2.4 pmole/mg蛋白降低至1.4 pmole/mg蛋白。这些研究表明，PTA-POA的重氮盐可能是人血小板TXA 2-PGH 2受体的一个有用的光亲和配体。
Abstract The diazonium salt of 9, 11-dimethylmethano-11, 12-methano-16-(4-aminophenoxy) 13, 14-dihydro-13-aza-15αβ-ω-tetranor TXA 2 (PTA-POA) was synthesized and used as a photoaffinity ligand for the putative human platelet TXA 2 PGH 2 receptor. Incubation of human platelet membranes with the diazonium salt of PTA-POA followed by photolysis at 290 nm (hν) resulted in a 40% decrease in the specific binding of [125 I] PTA-OH as measured in the radioligand binding assay. Co-incubation with a TXA 2 PGH 2 agonist followed by photolysis resulted in no decrease in specific binding. Incubation of the diazonium salt of PTA-POA with solubilized platelet membranes without photolysis followed by Scatchard analysis resulted in no change in the K d for [125 I] PTA-OH (38 nM) and the preparation which was incubated with the diazonium salt (42 nM). However, the B max for [125 I] PTA-OH binding was reduced from 2.4 pmole/mg protein for control to 1.4 pmole/mg protein. These studies show that the diazonium salt of PTA-POA may be a useful photoaffinity ligand for human platelet TXA 2 PGH 2 receptors.