Defense Mechanism of Phosphorothioated DNA under Peroxynitrite-Mediated Oxidative Stress
Defense Mechanism of Phosphorothioated DNA under Peroxynitrite-Mediated Oxidative Stress
复制标题
过亚硝酸盐介导的氧化应激下硫代磷酸化 DNA 的防御机制
DOI：
10.1021/acschembio.0c00591
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发表时间：
2020-09-18
影响因子：
4
通讯作者：
Zhao, Yi-Lei
中科院分区：
文献类型：
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作者：
Huang, Qiang;Li, Jiayi;Zhao, Yi-Lei
DNA硫代磷酸化（PT）存在于许多病原菌中，然而PT-DNA抵抗免疫应答的机制尚不清楚。在这项工作中，我们仔细研究了过氧亚硝酸盐（PN）的耐受性，使用PT生物工程E。大肠杆菌菌株。体内实验证实，S+菌株比S菌株在中度氧化应激下存活得更好。LCMS、IC和GCMS实验证明硫代磷酸酯部分转化为磷酸盐，并且副产物包括硫酸盐和元素硫。当使用O，O-二乙基硫代磷酸酯（DETP）时，在35 ℃和pH 8.0下，对于硫代磷酸酯和过氧亚硝酸盐，反应速率k（1）被确定为4.3 +/-0.5 M-1 s（1）。与DETP相比，硫代磷酸二核苷酸的IC 50值显著增加了400 - 700倍。SH/OH阴阳机制使原位DNA对PN介导的氧化应激的自我防御合理化，其代价是DNA修饰的额外生物能量。
DNA phosphorothioation (PT) exists in many pathogenic bacteria; however, the mechanism of PT-DNA resistance to the immune response is unclear. In this work, we meticulously investigated the peroxynitrite (PN) tolerance using PT-bioengineered E. coli strains. The in vivo experiment confirms that the S+ strain survives better than the S strain under moderately oxidative stress. The LCMS, IC, and GCMS experiments demonstrated that phosphorothioate partially converted to phosphate, and the byproduct included sulfate and elemental sulfur. When O,O-diethyl thiophosphate ester (DETP) was used, the reaction rate k(1) was determined to be 4.3 +/- 0.5 M-1 s(1) in the first-order for both phosphorothioate and peroxynitrite at 35 degrees C and pH of 8.0. The IC50 values of phosphorothioate dinucleotides are dramatically increased by 400700-fold compared to DETP. The SH/OH Yin-Yang mechanism rationalizes the in situ DNA self-defense against PN-mediated oxidative stress at the extra bioenergetic cost of DNA modification.