Structural characterization of cystathionine γ-lyase smCSE enables aqueous metal quantum dot biosynthesis.
Structural characterization of cystathionine γ-lyase smCSE enables aqueous metal quantum dot biosynthesis.
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DOI：
10.1016/j.ijbiomac.2021.01.141
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发表时间：
2021-01
影响因子：
8.2
通讯作者：
Yutong Wang;Huai Chen;Zhaoxia Huang;Mei Yang;Hailing Yu;Maochen Peng;Zhenyu Yang;Shoudeng Chen
中科院分区：
文献类型：
--
作者：
Yutong Wang;Huai Chen;Zhaoxia Huang;Mei Yang;Hailing Yu;Maochen Peng;Zhenyu Yang;Shoudeng Chen
无机材料生物合成的开发和利用已演变为单大分子体系。嗜麦芽窄食单胞菌的胞硫醚γ裂解酶是新近发现的一种能够合成纳米材料的生物分子。由于缺乏结构信息，smCSE的生物合成机制尚不清楚。在这里，我们获得了两个原子分辨的smCSE形式的X射线结构，并证实了酶活性中心内Tyr108和Lys206的构象变化对于蛋白质驱动的金属硫化物量子点(QD)的合成是至关重要的。四聚体的结构稳定性和表面氨基酸的专一性是SMCSE合成量子点的基础。QD产物的大小可以由预先设计的氨基酸来调节，其形态可以通过蛋白水解法来控制。通过与十二肽融合的工程蛋白的X射线结构显示，活性部位的柔性环的稳定提高了生长速度。我们进一步证明了SMCSE驱动的合成路线可以应用于其他金属硫化物纳米颗粒的一般合成。这些结果为更好地理解QD生物合成的机制和通过蛋白质修饰控制QD生物合成提供了新的视角。
The development and utilization of inorganic material biosynthesis have evolved into single macromolecular systems. A putative cystathionine γ-lyase of bacteriaStenotrophomonas maltophilia(smCSE) is a newly identified biomolecule that enables the synthesis of nanomaterials. Due to the lack of structural information, the mechanism of smCSE biosynthesis remains unclear. Herein, we obtain two atomic-resolution smCSE-form X-ray structures and confirm that the conformational changes of Tyr108 and Lys206 within the enzyme active sites are critical for the protein-driven synthesis of metal sulfide quantum dots (QDs). The structural stability of tetramer and the specificity of surface amino acids are the basis for smCSE to synthesize quantum dots. The size of QD products can be regulated by predesigned amino acids and the morphology can be controlled through proteolytic treatments. The growth rate is enhanced by the stabilization of a flexible loop in the active site, as shown by the X-ray structure of the engineered protein which fused with a dodecapeptide. We further prove that the smCSE-driven route can be applied to the general synthesis of other metal sulfide nanoparticles. These results provide a better understanding of the mechanism of QD biosynthesis and a new perspective on the control of this biosynthesis by protein modification.