Kohno H, Kanno T
Biochem J. 1985 Feb 15;226(1):59-65. doi: 10.1042/bj2260059.
Human peripheral lymphocytes were found to contain at least two distinct aminopeptidases, designated cytosol aminopeptidase and microsomal aminopeptidase, which differed from one another with respect to intracellular localization, substrate specificity, metal-ion activation, Km value and electrophoretic mobility. No change in these aminopeptidase activities was observed in cultured lymphocytes in the absence of mitogen throughout the cultivation period. The addition of phytohaemagglutinin or concanavalin A to the culture medium caused, in dose-dependent manner, a significant increase in cytosol aminopeptidase activity in lymphocytes. On the other hand, no increase in microsomal aminopeptidase activity was observed under the same conditions. The biochemical properties of aminopeptidases in stimulated cultured lymphocytes were identical with those of the enzymes in peripheral lymphocytes and unstimulated cultured lymphocyte. The phytohaemagglutinin dose-response curves for lymphocyte activation as measured by the DNA synthesis rate and for cytosol aminopeptidase activity were observed to be similar. However, when DNA synthesis was temporarily blocked by hydroxyurea, the rate of increase of aminopeptidase activity was unaffected. Pokeweed mitogen only slightly increased the cytosol aminopeptidase activity in cultured lymphocytes, although the lymphocytes were highly activated.
人们发现人类外周淋巴细胞至少含有两种不同的氨肽酶，分别称为胞质溶胶氨肽酶和微粒体氨肽酶，它们在细胞内定位、底物特异性、金属离子激活、米氏常数（Km值）和电泳迁移率方面彼此不同。在整个培养期间，在无有丝分裂原的情况下培养淋巴细胞，未观察到这些氨肽酶活性有变化。向培养基中添加植物血凝素或刀豆球蛋白A会以剂量依赖的方式导致淋巴细胞中胞质溶胶氨肽酶活性显著增加。另一方面，在相同条件下未观察到微粒体氨肽酶活性增加。受刺激的培养淋巴细胞中氨肽酶的生化特性与外周淋巴细胞和未受刺激的培养淋巴细胞中的酶的生化特性相同。通过DNA合成速率测量的淋巴细胞激活的植物血凝素剂量反应曲线与胞质溶胶氨肽酶活性的曲线相似。然而，当DNA合成被羟基脲暂时阻断时，氨肽酶活性的增加速率不受影响。尽管淋巴细胞被高度激活，但商陆有丝分裂原仅略微增加培养淋巴细胞中胞质溶胶氨肽酶的活性。
