A ribonuclease zymogen activated by the NS3 protease of the hepatitis C virus
A ribonuclease zymogen activated by the NS3 protease of the hepatitis C virus
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DOI：
10.1111/j.1742-4658.2006.05536.x
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发表时间：
2006-12-01
期刊：
影响因子：
5.4
通讯作者：
Raines, Ronald T.
中科院分区：
文献类型：
--
作者：
Johnson, R. J.;Lin, Shawn R.;Raines, Ronald T.
翻译蛋白酶作为无活性前体或酶原，保护细胞免受不调节的蛋白水解活性的潜在致命作用。在这里，我们通过创造一种酶原，将这种策略施加于牛胰腺核糖核酸酶（RNase A）上，在这种酶原中，静止的核糖核酸溶解活性被丙型肝炎病毒的NS3蛋白酶激活。研究发现，将RNase A的n端和c端与一个14个残基的连接物连接，可以通过阻断RNA底物和使活性位点残基错位来降低其核糖核分解活性，这是天然酶原使用的设备。在NS3蛋白酶裂解连接体后，RNase A酶原的核糖核分解活性增加了105倍。在激活前和激活后，RNase A酶原均表现出较高的构象稳定性和逃避内源性核糖核酸酶抑制蛋白的能力。因此，核糖核酸酶酶原的创造提供了一种控制核糖核溶解活性的手段，并有可能提供一类新的抗病毒化疗药物。
Translating proteases as inactive precursors, or zymogens, protects cells from the potentially lethal action of unregulated proteolytic activity. Here, we impose this strategy on bovine pancreatic ribonuclease (RNase A) by creating a zymogen in which quiescent ribonucleolytic activity is activated by the NS3 protease of the hepatitis C virus. Connecting the N-terminus and C-terminus of RNase A with a 14-residue linker was found to diminish its ribonucleolytic activity by both occluding an RNA substrate and dislocating active-site residues, which are devices used by natural zymogens. After cleavage of the linker by the NS3 protease, the ribonucleolytic activity of the RNase A zymogen increased 105-fold. Both before and after activation, the RNase A zymogen displayed high conformational stability and evasion of the endogenous ribonuclease inhibitor protein of the mammalian cytosol. Thus, the creation of ribonuclease zymogens provides a means to control ribonucleolytic activity and has the potential to provide a new class of antiviral chemotherapeutic agents.