Serine proteases as candidates for proteolytic processing of angiotensin-I converting enzyme
Serine proteases as candidates for proteolytic processing of angiotensin-I converting enzyme
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DOI：
10.1016/j.ijbiomac.2014.09.017
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发表时间：
2015-01-01
影响因子：
8.2
通讯作者：
Casarini, Dulce Elena
中科院分区：
文献类型：
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作者：
Aragao, Danielle S.;de Andrade, Maria Claudina C.;Casarini, Dulce Elena
体细胞血管紧张素转换酶(SACE)是一种广泛分布的肽酶，它通过将血管紧张素I转化为血管紧张素II来调节血压和电解质的稳态。N结构域亚型(NACE)在体液、组织和系膜细胞(MC)中分别为65和90 kDa，90 kDa的NACE仅在自发性高血压大鼠中被发现。本研究的目的是研究MC中蛋白水解酶的存在，这些酶可能在MC中产生SACE的NACE的水解酶中起作用。在证实永生化MC(IMC)中存在ACE脱落酶后，我们使用专为ACE脱落酶设计的荧光底物纯化和鉴定了这些酶。纯化的酶经N-末端测序证实为丝氨酸蛋白酶，可产生NACE。在本研究中，我们首次描述了血管紧张素转换酶在血管内皮细胞中的存在，这种酶被鉴定为能够在体外降解SACE的丝氨酸蛋白酶。ACE脱落酶在MC中表达和调控的机制及其在NACE，特别是可能与高血压相关的90 kDa形式NACE的发生中的作用有待进一步研究。(C)2014爱思唯尔B.V.保留所有权利。
Somatic angiotensin-I converting enzyme (sACE) is a broadly distributed peptidase which plays a role in blood pressure and electrolyte homeostasis by the conversion of angiotensin I into angiotensin II. N-domain isoforms (nACE) with 65 and 90 kDa have been described in body fluids, tissues and mesangial cells (MC), and a 90 kDa nACE has been described only in spontaneously hypertensive rats. The aim of this study was to investigate the existence of proteolytic enzymes that may act in the hydrolysis of sACE generating nACEs in MC. After the confirmation of the presence of ACE sheddases in Immortalized MC (IMC), we purified and characterized these enzymes using fluorogenic substrates specifically designed for ACE sheddases. Purified enzyme identified as a serine protease by N-terminal sequence was able to generate nACE. In the present study, we described for the first time the presence of ACE sheddases in IMC, identified as serine proteases able to hydrolyze sACE in vitro. Further investigations are necessary to elucidate the mechanisms responsible for the expression and regulation of ACE sheddases in MC and their roles in the generation of nACEs, especially the 90 kDa form possibly related to hypertension. (C) 2014 Elsevier B.V. All rights reserved.