Protein disulfide isomerase activity is released by activated platelets
Protein disulfide isomerase activity is released by activated platelets
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DOI：
10.1182/blood.v79.9.2226.bloodjournal7992226
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发表时间：
1992-05
期刊：
影响因子：
20.3
通讯作者：
Kui Chen;Yin Lin;T. Detwiler
中科院分区：
文献类型：
--
作者：
Kui Chen;Yin Lin;T. Detwiler
蛋白二硫键异构酶的释放是基于报道的分子间和分子内的硫醇-二硫键交换和二硫化物还原涉及在激活的血小板的上清液中释放的凝血酶响应素(Danishefsky，Alexander，Detwiler：BioChemical，23：4984,1984；Speziale，Detwiler：J Biol Chem，265：17859,1990；Speziale，Detwiler：Arch Biochem BiPhys286：546,1991)。在血小板活化后的上清液中检测蛋白质二硫键异构酶活性，通过催化二硫键失活的核糖核酸酶的复性来测量。已知的抑制蛋白二硫键异构酶的多肽抑制了这种活性；这些多肽还抑制了二硫键连接的凝血酶反应蛋白-凝血酶复合体的形成。上清液催化的反应表现出与非催化反应不同的pH依赖性。用50kD透析膜排除其活性，并在凝胶过滤柱的空隙体积中洗脱，表明它与大分子有关。100000克离心150分钟不能去除该酶的活性，表明该酶与膜微囊无关。讨论了活化的血小板释放蛋白二硫键异构酶的可能功能。
The release of protein disulfide isomerase by activated platelets was hypothesized on the basis of reported intermolecular and intramolecular thiol-disulfide exchange and disulfide reduction involving released thrombospondin in the supernatant solution of activated platelets (Danishefsky, Alexander, Detwiler: Biochemistry, 23:4984, 1984; Speziale, Detwiler: J Biol Chem, 265:17859, 1990; Speziale, Detwiler: Arch Biochem Biophys 286:546, 1991). Protein disulfide isomerase activity, measured by catalysis of the renaturation of ribonuclease inactivated by randomization of disulfide bonds, was detected in the supernatant solution after platelet activation. The activity was inhibited by peptides known to inhibit protein disulfide isomerase; the peptides also inhibited formation of disulfide-linked thrombospondin- thrombin complexes. The reaction catalyzed by the supernatant solution showed a pH dependence distinct from that of the uncatalyzed reaction. The activity was excluded by a 50-Kd dialysis membrane, and it was eluted in the void volume of a gel-filtration column, indicating that it was associated with a macromolecule. The activity was not removed by centrifugation at 100,000 g for 150 minutes indicating that it was not associated with membrane microvesicles. Possible functions for the release of protein disulfide isomerase by activated platelets are discussed.