Proteolytic enzymes of lung.
Proteolytic enzymes of lung.
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肺的蛋白水解酶。
DOI：
10.1016/s0021-9258(18)66016-8
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发表时间：
1955
影响因子：
4.8
通讯作者：
E. L. Smith
中科院分区：
文献类型：
--
作者：
A. Dannenberg;E. L. Smith
肺通常被认为是被动组织，其主要功能是允许气体扩散到血液和从血液扩散；然而，肺也是一个防御器官。它的吞噬细胞可以清除吸入的尘埃颗粒和细菌。肺实质相当一部分由单核巨噬细胞和潜在的单核巨噬细胞组成。由于这些细胞不是很容易获得，我们对肺的蛋白水解酶进行了调查，以期最终将这些信息与单核吞噬细胞的酶相关联，并有助于了解结核病的液化过程。Fruton(1)证明在兔肺提取物中存在亮氨酸氨基肽酶、三肽酶和甘氨酸二肽酶。他没有检测到包括苯甲酰-L-精氨酰胺在内的几种蛋白水解酶的合成底物的水解。然而，Weiss和Halliday(2)报道了在兔肺中存在一种水解苯甲酰-L-精氨酰胺的酶。Nye(3)和Weiss(4)也在肺中发现了一种最适pH为3到4的蛋白酶。本研究证实了Fruton(1)对肺多肽酶的工作，并报告了另外两种多肽酶的存在。我们还发现，肺提取液有两个区域的蛋白酶活性，一个是在酸性pH(蛋白酶I)，另一个是在碱性pH(蛋白酶II)。本文介绍了一种分离纯化蛋白酶I的方法及其部分性质。对其特异性的进一步研究在其他地方给出(5)。已发现一种合成底物N-乙酰-L-酪氨酸乙酯，用于蛋白酶II的一个组分，但该组分的纯化尚未尝试。
The lung usually is considered to be a passive tissue whose main function is to permit gaseous diffusion to and from the blood; however, the lung is also an organ of defense. Its phagocytes remove inhaled dust particles and bacteria. A considerable part of the lung parenchyma consists of mononuclear phagocytes and potential mononuclear phagocytes. Since these cells are not readily available in quantity, a survey of the proteolytic enzymes of lung was made with the hope that such information could be correlated eventually with the enzymes of the mononuclear phagocytes as well as be helpful in understanding the liquefaction’process of tuberculosis.Fruton (1) demonstrated the presence of leucine aminopeptidase, tripeptidase, and glycylglycine dipeptidase in extracts of rabbit lung. He could detect no hydrolysis of the synthetic substrates for several proteinases, including benzoyl-L-argininamide. Weiss and Halliday (2), however, have reported the presence of an enzyme in rabbit lung which hydrolyzes benzoyl-L-argininamide. Nye (3) and Weiss (4) have also identified a proteinase in lung that is optimally active at pH 3 to 4. The present study confirms the work of Fruton (1) on the peptidases of lung and reports the presence of two additional peptidases. We have also found that lung extracts show two regions of proteinase activity, one at acid pH (Proteinase I) and another at alkaline pH (Proteinase II). A method of purification and some of the properties of Proteinase I are described. Further studies of its specificity are given elsewhere (5). A synthetic substrate, N-acetyl-L-tyrosine ethyl ester, has been found for a component of Proteinase II, but purification of this fraction has not been attempted as yet.