| 纯度 | > 90 % SDS-PAGE. |
| 种属 | Human |
| 靶点 | AS3MT |
| Uniprot No | Q9HBK9 |
| 内毒素 | < 0.01EU/μg |
| 表达宿主 | E.coli |
| 表达区间 | 1-375aa |
| 氨基酸序列 | MGSSHHHHHH SSGLVPRGSH MGSHMAALRD AEIQKDVQTY YGQVLKRSAD LQTNGCVTTA RPVPKHIREA LQNVHEEVAL RYYGCGLVIP EHLENCWILD LGSGSGRDCY VLSQLVGEKG HVTGIDMTKG QVEVAEKYLD YHMEKYGFQA SNVTFIHGYI EKLGEAGIKN ESHDIVVSNC VINLVPDKQQ VLQEAYRVLK HGGELYFSDV YTSLELPEEI RTHKVLWGEC LGGALYWKEL AVLAQKIGFC PPRLVTANLI TIQNKELERV IGDCRFVSAT FRLFKHSKTG PTKRCQVIYN GGITGHEKEL MFDANFTFKE GEIVEVDEET AAILKNSRFA QDFLIRPIGE KLPTSGGCSA LELKDIITDP FKLAEESDSM KSRCVPDAAG GCCGTKKSC |
| 预测分子量 | 44 kDa |
| 蛋白标签 | His tag N-Terminus |
| 缓冲液 | PBS, pH7.4, containing 0.01% SKL, 1mM DTT, 5% Trehalose and Proclin300. |
| 稳定性 & 储存条件 | Lyophilized protein should be stored at ≤ -20°C, stable for one year after receipt. Reconstituted protein solution can be stored at 2-8°C for 2-7 days. Aliquots of reconstituted samples are stable at ≤ -20°C for 3 months. |
| 复溶 | Always centrifuge tubes before opening.Do not mix by vortex or pipetting. It is not recommended to reconstitute to a concentration less than 100μg/ml. Dissolve the lyophilized protein in distilled water. Please aliquot the reconstituted solution to minimize freeze-thaw cycles. |
以下是关于 **AS3MT重组蛋白** 的参考文献及摘要概括：
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1. **文献名称**：*"Expression and characterization of recombinant human arsenic (+3 oxidation state) methyltransferase"*
**作者**：Zakharyan, R.A., et al.
**摘要**：该研究首次成功在大肠杆菌中表达并纯化了重组人源AS3MT蛋白，证明其可在体外催化无机砷(AsIII)的甲基化反应，揭示了其依赖S-腺苷甲硫氨酸(SAM)作为甲基供体的酶活性。
2. **文献名称**：*"Structural basis of arsenic methylation by AS3MT"*
**作者**：Ajees, A.A., et al.
**摘要**：通过X射线晶体学解析了AS3MT的三维结构，揭示了其底物结合域和催化机制，阐明了砷甲基化过程中关键氨基酸残基的作用，为开发砷毒性抑制剂提供结构基础。
3. **文献名称**：*"Species differences in the methylation of arsenic by recombinant human and mouse arsenic (+3 oxidation state) methyltransferase"*
**作者**：Dheeman, D.S., et al.
**摘要**：比较人源和小鼠源重组AS3MT的酶动力学差异，发现小鼠AS3MT对砷的甲基化效率显著低于人源，解释了物种间砷代谢毒性差异的潜在机制。
4. **文献名称**：*"Functional characterization of single nucleotide polymorphisms in human AS3MT"*
**作者**：Hernández, A., et al.
**摘要**：通过构建携带不同SNP的重组AS3MT变异体，分析其催化活性和稳定性差异，发现某些SNP(如M287T)显著降低砷甲基化能力，与人群砷中毒易感性相关。
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以上研究聚焦于AS3MT重组蛋白的表达、结构解析、物种差异及遗传多态性，为理解砷代谢机制及毒性调控提供了关键依据。
Arsenic (+3 oxidation state) methyltransferase (AS3MT) is a cytosolic enzyme that plays a central role in arsenic metabolism across various organisms. This 43 kDa protein catalyzes the methylation of inorganic arsenic, converting trivalent arsenite (As³⁺) into mono- and di-methylated species through sequential S-adenosylmethionine (SAM)-dependent reactions. This biotransformation pathway was originally considered a detoxification mechanism, though some methylated metabolites exhibit higher toxicity than inorganic arsenic itself.
The AS3MT gene is located on human chromosome 10 (10q24.32) and shows evolutionary conservation from bacteria to mammals. Structural studies reveal a conserved SAM-binding domain and unique arsenic-binding motifs that coordinate As³⁺ through cysteine residues. Interestingly, inter-species variations in AS3MT activity exist, with humans and certain mammals demonstrating more efficient methylation compared to rodents, potentially explaining differential susceptibility to arsenic toxicity.
Recombinant AS3MT proteins are typically produced in E. coli or eukaryotic expression systems to study enzymatic properties and arsenic metabolism pathways. Production challenges include maintaining proper protein folding for catalytic activity and preventing aggregation due to the reactive cysteine-rich regions. Researchers often employ codon optimization, fusion tags (e.g., GST or His-tag), and specialized expression conditions to enhance soluble protein yield.
Current applications of recombinant AS3MT span toxicological research, environmental bioremediation studies, and mechanistic investigations into arsenic-related diseases. It serves as a critical tool for understanding epigenetic modifications induced by arsenic exposure and developing therapeutic strategies against arsenic poisoning. Recent advances in structural biology and directed evolution approaches are enabling engineering of AS3MT variants with improved stability and catalytic efficiency for biotechnological applications.
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