Structural and biochemical characterization of Arabidopsis alcohol dehydrogenases reveals distinct functional properties but similar redox sensitivity
Structural and biochemical characterization of Arabidopsis alcohol dehydrogenases reveals distinct functional properties but similar redox sensitivity
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拟南芥醇脱氢酶的结构和生化特征揭示了不同的功能特性但相似的氧化还原敏感性
DOI：
10.1111/tpj.16651
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Vierling, Elizabeth
中科院分区：
文献类型：
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作者：
Meloni, Maria;Rossi, Jacopo;Fanti, Silvia;Carloni, Giacomo;Tedesco, Daniele;Treffon, Patrick;Piccinini, Luca;Falini, Giuseppe;Trost, Paolo;Vierling, Elizabeth
乙醇脱氢酶（ADH）是属于中等长度脱氢酶/还原酶（MDR）蛋白超家族的一组锌结合酶。在植物中，这些酶履行重要的功能，包括将有毒醛还原为相应的醇（以及催化逆反应，即，乙醇氧化; ADH 1）和亚硝基谷胱甘肽的还原（GSNO; ADH 2/GSNOR）。我们研究并比较了拟南芥ADH 1和GSNOR的结构和生化特性。我们表达并纯化了ADH 1和GSNOR，并确定了两种新的结构，NADH-ADH 1和apo-GSNOR，从而完成了拟南芥ADH在apo-和holo-形式中的结构景观。这些拟南芥ADH的结构比较揭示了高的序列保守性（59%的同一性）和相似的倍。相反，在支持底物特异性和适应性的催化腔中观察到显著的不同。一致的是，ADH 1和GSNOR对其底物（分别为乙醇和GSNO）显示出严格的特异性，尽管这两种酶都具有氧化长链醇的能力，其中ADH 1的表现优于GSNOR。这两种酶都含有大量的半胱氨酸（ADH 1和GSNOR的379个残基中分别有12个和15个），并且对硫醇氧化剂显示出显著且相似的响应性，表明氧化还原修饰可能构成了在最佳生长和胁迫条件下控制酶活性的机制。
Alcohol dehydrogenases (ADHs) are a group of zinc‐binding enzymes belonging to the medium‐length dehydrogenase/reductase (MDR) protein superfamily. In plants, these enzymes fulfill important functions involving the reduction of toxic aldehydes to the corresponding alcohols (as well as catalyzing the reverse reaction, i.e., alcohol oxidation; ADH1) and the reduction of nitrosoglutathione (GSNO; ADH2/GSNOR). We investigated and compared the structural and biochemical properties of ADH1 and GSNOR fromArabidopsis thaliana. We expressed and purified ADH1 and GSNOR and determined two new structures, NADH‐ADH1 and apo‐GSNOR, thus completing the structural landscape of Arabidopsis ADHs in both apo‐ and holo‐forms. A structural comparison of these Arabidopsis ADHs revealed a high sequence conservation (59% identity) and a similar fold. In contrast, a striking dissimilarity was observed in the catalytic cavity supporting substrate specificity and accommodation. Consistently, ADH1 and GSNOR showed strict specificity for their substrates (ethanol and GSNO, respectively), although both enzymes had the ability to oxidize long‐chain alcohols, with ADH1 performing better than GSNOR. Both enzymes contain a high number of cysteines (12 and 15 out of 379 residues for ADH1 and GSNOR, respectively) and showed a significant and similar responsivity to thiol‐oxidizing agents, indicating that redox modifications may constitute a mechanism for controlling enzyme activity under both optimal growth and stress conditions.