Understanding the relationships between solubility, stability, and activity of silicatein
Understanding the relationships between solubility, stability, and activity of silicatein
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DOI：
10.1039/d2ma00938b
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发表时间：
2022-12-15
影响因子：
5
通讯作者：
Berger，Bryan W.
中科院分区：
文献类型：
--
作者：
Vigil，Toriana N.;Rowson，Mary-Jean C.;Berger，Bryan W.
硅酸盐是一种酶，可将环境前体矿化为图案化纳米材料，并且被发现可以自然地协调海洋海绵复杂而美丽的外骨骼。为了利用这种活性进行纳米材料生物制造，酶的溶解度和稳定性已得到广泛研究。我们通过蛋白质融合标签解决酶的溶解度挑战：增强型绿色荧光蛋白 (eGFP)、单体超级文件夹 GFP (msGFP2) 和触发因子 (TF)。所有三种硅酸盐融合蛋白均不同程度地形成寡聚体，并部分受到二硫桥的调节。使用二氧化硅和纳米陶瓷评估生物矿化活性，显示 eGFP-硅酸盐和 TF-硅酸盐的产率相当，并且无论二硫桥还原如何，矿化产物的组成都相同，这通过硅酸盐纳米晶产品的 XRD 表征显示。这意味着溶解度对硅酸盐活性只有很小的影响，并且目前在该领域的持续改进是不必要的。此外，这些结果表明硅酸盐生物矿化活性是酶本身固有的。因此，未来的研究应该旨在了解硅酸盐的动力学机制。
Silicatein is an enzyme that mineralizes environmental precursors to patterned nanomaterials and is found naturally orchestrating the complex and beautiful exoskeletons of marine sponges. To harness this activity for nanomaterial biomanufacturing, enzyme solubility and stability have been widely studied. We address the enzyme's solubility challenge via protein fusion tags: enhanced green fluorescent protein (eGFP), monomeric superfolder GFP (msGFP2), and trigger factor (TF). All three silicatein fusion proteins form oligomers to varying degrees, that are partially modulated by disulfide bridges. Biomineralization activity was assessed with silica and nanoceria, showing comparable yields for eGFP-silicatein and TF-silicatein, as well as identical composition of mineralized products regardless of disulfide bridge reduction, shown via XRD characterization of silicatein's nanocrystalline product. This implies that solubility has only minor effects on silicatein activity and that continued improvement in this area is currently inessential. Furthermore, these results suggest that silicatein biomineralization activity is inherent to the enzyme itself. Thus, future studies should be aimed at understanding silicatein's kinetic mechanisms.