Wedner H J, Chan B Y, Parker C S, Parker C W
J Immunol. 1979 Aug;123(2):725-32.
cAMP and cGMP phosphodiesterase (PDE) activity was assayed in human peripheral blood lymphocytes purified by isopycnic centrifugation as well as in lymphocyte preparations further purified to remove contaminating platelets and monocytes. The 16,000 X G supernatant from sonicates of each of these cell preparations contained two hydrolytic activities for cAMP with apparent Km of 1.1 to 2.5 microM and 33 to 66 microM, and a single hydrolytic activity for cGMP with an apparent Km of 6 to 25 microM. When lymphocytes were disrupted by Dounce homogenization, there was only a single, low Km cAMP PDE activity in the homogenate; however, the 16,000 X G supernatant demonstrated 2 Km similar to that seen in sonicated lymphocytes. Treatment of the Dounce preparations with 0.5% Triton X-100 or 1.0% NP-40 converted these preparations to activities similar to those seen in sonicated preparations. cGMP hydrolytic activity was low or absent in the Dounce preparations and was not altered by centrifugation; however, it was markedly enhanced by detergent extraction. These data indicate that human peripheral blood lymphocytes and monocytes have PDE activities similar to those seen in other tissues.
采用等密度离心法纯化的人外周血淋巴细胞以及进一步纯化以去除污染的血小板和单核细胞的淋巴细胞制剂中，检测了环磷酸腺苷（cAMP）和环磷酸鸟苷（cGMP）磷酸二酯酶（PDE）的活性。这些细胞制剂的超声破碎物经16,000×重力离心后的上清液中，含有两种对cAMP具有水解活性的酶，其表观米氏常数（Km）分别为1.1至2.5微摩尔和33至66微摩尔，以及一种对cGMP具有水解活性的酶，其表观Km为6至25微摩尔。当淋巴细胞通过玻璃匀浆器匀浆破碎时，匀浆中仅有一种低Km的cAMP PDE活性；然而，16,000×重力离心后的上清液显示出与超声破碎的淋巴细胞中相似的两种Km。用0.5% Triton X - 100或1.0% NP - 40处理玻璃匀浆器制备物后，这些制备物的活性转变为与超声破碎制备物中所见的活性相似。玻璃匀浆器制备物中的cGMP水解活性较低或不存在，且不受离心的影响；然而，通过去污剂提取可使其显著增强。这些数据表明，人外周血淋巴细胞和单核细胞具有与其他组织中所见相似的PDE活性。
