Trypsin activation, partial characterization, and distribution of kallikrein-like and thrombin-like proteases in the neurointermediate lobe of the rat pituitary.
Trypsin activation, partial characterization, and distribution of kallikrein-like and thrombin-like proteases in the neurointermediate lobe of the rat pituitary.
复制标题
大鼠垂体神经中叶中激肽释放酶样和凝血酶样蛋白酶的胰蛋白酶激活、部分表征和分布。
DOI：
10.1111/j.1471-4159.1986.tb02842.x
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发表时间：
1986
影响因子：
4.7
通讯作者：
Powers,CA
中科院分区：
文献类型：
--
作者：
Powers,CA
本研究检测了大鼠垂体神经中间叶（NIL）是否含有胰蛋白酶激活的潜在激肽释放酶和凝血酶样蛋白酶。尝试对这些蛋白酶进行部分表征。还检查了NIL内蛋白水解活性的分布以及雄性和雌性肺叶中的水平。在与胰蛋白酶（10 μg/ml）孵育前后，在pH 8.0下测定NIL匀浆的蛋白水解活性。胰蛋白酶在NIL匀浆中引起10倍的激肽释放酶样活性活化和40倍的凝血酶样活性活化。使用二乙基氨基乙基-葡聚糖凝胶将激肽释放酶样活性分离成两种组分。主要的激肽释放酶样蛋白酶是一种与腺激肽释放酶密切相关或相同的强效激肽原酶，并且几乎完全定位于中叶。第二种激肽释放酶样蛋白酶（激肽释放酶A）是一种对大豆胰蛋白酶抑制剂和抑肽酶的抑制敏感的弱激肽原酶，并且在神经叶和中叶中的浓度相似。凝血酶样蛋白酶对水蛭素（一种特异性凝血酶抑制剂）和凝血纤维蛋白原的抑制敏感，并且在神经叶中的浓度略高于中叶。来自雌性大鼠的NIL含有的激肽释放酶活性比来自雄性大鼠的NIL低约40%，但它们的凝血酶样活性含量没有差异。
This study examined whether the neurointermediate lobe (NIL) of the rat pituitary contains latent kallikrein‐ and thrombin‐like proteases activated by trypsin. Partial characterization of such proteases was attempted. Also examined were the distribution of proteo‐lytic activity within the NIL and levels in both male and female lobes. NIL homogenates were assayed for proteo‐lytic activity at pH 8.0 before and after incubation with trypsin (10 μg/ml). Trypsin caused a 10‐fold activation of kallikrein‐like activity and a 40‐fold activation of thrombin‐like activity in NIL homogenates. The kallikrein‐like activity was separated into two components using diethylaminoethyl‐Sephadex. The predominant kallikrein‐like protease was a potent kininogenase closely related or identical to glandular kallikrein and was almost exclusively localized to the intermediate lobe. The second kallikrein‐like protease (kallikrein A) was a weak kininogenase sensitive to inhibition by both soybean trypsin inhibitor and aprotinin and was similarly concentrated in both the neural lobe and the intermediate lobe. The thrombin‐like protease was sensitive to inhibition by hirudin (a specific thrombin inhibitor), clotted fibrinogen, and was slightly more concentrated in the neural lobe than in the intermediate lobe. NILs from female rats contained ∼40% less kallikrein activity than NILs from male rats but did not differ in their content of thrombin‐like activity.