Concurrent methylation and demethylation of arsenic by fungi and their differential expression in the protoplasm proteome.
Concurrent methylation and demethylation of arsenic by fungi and their differential expression in the protoplasm proteome.
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DOI：
10.1016/j.envpol.2017.03.030
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发表时间：
2017-06
影响因子：
8.9
通讯作者：
S. Su;X. Zeng;L. Bai;Yanan Wang;Lili Zhang;Mansheng Li;C. Wu
中科院分区：
文献类型：
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作者：
S. Su;X. Zeng;L. Bai;Yanan Wang;Lili Zhang;Mansheng Li;C. Wu
微生物甲基化和去甲基化是砷(As)生物地球化学循环的核心。本文研究了甲基化真菌尖孢镰刀菌CZ-8F1、简青霉SM-12F4和毛霉木霉SM-12F1在单甲基化真菌L−1中50 mg/L作用15天的转化情况，并观察到真菌细胞提取物中As(III)和As(V)的含量。在MMA(V)和简青霉SM-12F4的培养中也检测到了微量的DMA(V)。X射线吸收近缘结构分析表明，在真菌细胞中，甲基丙烯酸甲酯(V)(500m g L−1)作用15d后，28.6-48.6%的As是DMA(V)，其次是As(V)的18.4-30.3%，As(III)的0-28.1%，MMA(V)的4.8-28.9%。AS的甲基化和去甲基化同时发生在真菌细胞中。此外，与As(III)、As(V)和DMA(V)相比，MMA(V)处理的SM-12F1细胞中与代谢、运输、ATP活性、生物合成、信号转导、DNA活性、翻译和氧化应激有关的大部分蛋白质都上调了。Asperellum SM-12F1菌株的解毒过程具有种属特异性。甲基四氢叶酸还原酶(R7YMH0)对S-腺苷甲硫氨酸(SAM)生成的甲基贡献显著增加。
Microbial methylation and demethylation are central to arsenic's (As) biogeochemical cycling. Here, the transformations of monomethylarsonic acid (MMA(V)) (50 mg L−1) for 15 days in cells of As-methylating fungi,Fusarium oxysporumCZ-8F1,Penicillium janthinellumSM-12F4, andTrichoderma asperellumSM-12F1, were evaluated, and trace concentrations of As(III) and As(V) were observed in fungal cell extracts. Trace amounts of DMA(V) were also detected in MMA(V) andP.janthinellumSM-12F4 incubations. InsituX-ray absorption near edge structure (XANES) indicated that after exposure to MMA(V) (500 mg L−1) for 15 days, 28.6–48.6% of accumulated As in fungal cells was DMA(V), followed by 18.4–30.3% from As(V), 0–28.1% from As(III), and 4.8–28.9% from MMA(V). The concurrent methylation and demethylation of As occurs in fungal cells. Furthermore, a majority of proteins involved in metabolism, transport, ATP activity, biosynthesis, signal transduction, DNA activity, translation, and oxidative stress were upregulated inT. asperellumSM-12F1 cells after MMA(V) exposure compared to As(III), As(V), and DMA(V). The detoxification process ofT.asperellum SM-12F1 was As species-specific. Methylenetetrahydrofolate reductase (R7YMH0) donation of a methyl group for S-adenosylmethionine (SAM) generation significantly increased following MMA(V) exposure.