Chambers D A, Nachman R L, Evarts J, Kinoshita T
Biochim Biophys Acta. 1982 Nov 24;719(2):208-14. doi: 10.1016/0304-4165(82)90090-3.
Cyclic AMP inhibits platelet aggregation induced by physiological agents. 8 Azido [32P]cyclic AMP (N3 cyclic AMP) has been utilized as a photoaffinity probe to define the cyclic AMP-binding proteins present in unperturbed human platelets and their subcellular fractions. Specificity of cyclic AMP binding was determined by contrasting binding in the presence and absence of excess unlabelled cyclic AMP, cyclic GMP and 5'-AMP. Binding was unaffected by 5'-AMP and obliterated by cyclic AMP. Four major species of binding proteins, 49 000, 42 000, 39 000, 37 000, were obtained in all platelet fractions (crude homeogenate, cytosol, membranes and granules). Two-dimensional gel electrophoresis of platelet cytosol resolved the major molecular weight species into 15 specific cyclic AMP binding proteins of four molecular weight classes differing by charge density. These studies suggest that platelets contain an array of specific cyclic AMP-binding proteins which may function in hemostatic regulation.
环磷酸腺苷（cAMP）可抑制生理因子诱导的血小板聚集。8-叠氮基[32P]环磷酸腺苷（N3-cAMP）已被用作光亲和探针，以确定未受干扰的人血小板及其亚细胞组分中存在的环磷酸腺苷结合蛋白。通过对比在存在和不存在过量未标记环磷酸腺苷、环磷酸鸟苷（cGMP）和5'-腺苷酸（5'-AMP）的情况下的结合情况，确定了环磷酸腺苷结合的特异性。结合不受5'-AMP的影响，但被环磷酸腺苷消除。在所有血小板组分（粗匀浆、胞质溶胶、膜和颗粒）中均获得了四种主要的结合蛋白，分子量分别为49000、42000、39000和37000。血小板胞质溶胶的二维凝胶电泳将主要分子量的蛋白种类解析为15种特定的环磷酸腺苷结合蛋白，分为四个分子量类别，它们的电荷密度不同。这些研究表明，血小板含有一系列特定的环磷酸腺苷结合蛋白，它们可能在止血调节中发挥作用。
