A thiol redox sensor in soluble epoxide hydrolase enables oxidative activation by intra-protein disulfide bond formation.
A thiol redox sensor in soluble epoxide hydrolase enables oxidative activation by intra-protein disulfide bond formation.
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可溶性环氧化物水解酶中的硫醇氧化还原传感器可以通过蛋白质二硫键形成氧化激活。
DOI：
10.1016/j.redox.2021.102107
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发表时间：
2021-10
期刊：
影响因子：
11.4
通讯作者：
Eaton P
中科院分区：
文献类型：
--
作者：
Charles RL;Abis G;Fernandez BF;Guttzeit S;Buccafusca R;Conte MR;Eaton P
可溶性环氧化物水解酶（sEH）是一种广泛调节心血管系统的酶，其将环氧二十碳三烯酸（Epoxyeicosatrienoic Acids，EEP）水解为它们相应的二羟基二十碳三烯酸（dihydroxyeicosatrienoic Acids，DHEP）。我们以前发现，内源性脂质亲电体加合物的催化结构域，抑制sEH降低血压血管紧张素II诱导的高血压小鼠。由于血管紧张素II增加血管H2 O2，我们探讨了这种氧化剂的sEH氧化还原调节，以及如何将其与脂质亲电体的抑制作用结合起来调节血管紧张素。动力学分析表明，H_2O_2不仅提高了sEH的比活性，而且增加了其对底物的亲和力，提高了其催化效率。这种氧化活化介导的C262和C264之间形成一个内二硫键，通过质谱测定和证实的生物素-苯胂酸盐和硫氧还蛋白捕获突变体测定。C262 S/264 S sEH突变体对过氧化物诱导的活化具有抗性，证实了二硫化物活化机制。在离体动脉中测定sEH氧化还原状态的生理影响，并在小鼠中测定促氧化剂血管加压剂血管紧张素II对动脉sEH氧化还原状态和血管舒张性兴奋指数的影响。血管紧张素II诱导sEH中激活的内二硫键，导致血浆EET/DHET比值降低，这与对该激素的升压反应一致。尽管sEH C262-C264二硫化物的形成增强了血管舒张性E2的水解，但这种修饰也使sEH对脂质亲电体的抑制敏感。这就解释了为什么血管紧张素II会降低雌二醇并升高血压，但当脂质亲电体也存在时，雌二醇会升高，血压会降低。
Soluble epoxide hydrolase (sEH), an enzyme that broadly regulates the cardiovascular system, hydrolyses epoxyeicosatrienoic acids (EETs) to their corresponding dihydroxyeicosatrienoic acids (DHETs). We previously showed that endogenous lipid electrophiles adduct within the catalytic domain, inhibiting sEH to lower blood pressure in angiotensin II-induced hypertensive mice. As angiotensin II increases vascular H2O2, we explored sEH redox regulation by this oxidant and how this integrates with inhibition by lipid electrophiles to regulate vasotone. Kinetics analyses revealed that H2O2 not only increased the specific activity of sEH but increased its affinity for substrate and increased its catalytic efficiency. This oxidative activation was mediated by formation of an intra-disulfide bond between C262 and C264, as determined by mass spectrometry and substantiated by biotin-phenylarsinate and thioredoxin-trapping mutant assays. C262S/264S sEH mutants were resistant to peroxide-induced activation, corroborating the disulfide-activation mechanism. The physiological impact of sEH redox state was determined in isolated arteries and the effect of the pro-oxidant vasopressor angiotensin II on arterial sEH redox state and vasodilatory EETs indexed in mice. Angiotensin II induced the activating intra-disulfide in sEH, causing a decrease in plasma EET/DHET ratios that is consistent with the pressor response to this hormone. Although sEH C262–C264 disulfide formation enhances hydrolysis of vasodilatory EETs, this modification also sensitized sEH to inhibition by lipid electrophiles. This explains why angiotensin II decreases EETs and increases blood pressure, but when lipid electrophiles are also present, that EETs are increased and blood pressure lowered.
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影响因子：
7.4
作者：
Abis, Giancarlo;Pacheco-Gomez, Raul;Conte, Maria R.
通讯作者：
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影响因子：
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作者：
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影响因子：
20.1
作者：
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通讯作者：
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作者：
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