Genetically encoded conductive protein nanofibers secreted by engineered cells
Genetically encoded conductive protein nanofibers secreted by engineered cells
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DOI：
10.1039/c7ra06289c
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发表时间：
2017-01-01
期刊：
影响因子：
3.9
通讯作者：
Seker, Urartu Ozgur Safak
中科院分区：
文献类型：
--
作者：
Kalyoncu, Ebuzer;Ahan, Recep E.;Seker, Urartu Ozgur Safak
细菌生物膜作为生物纳米材料具有良好的应用前景。它们通过定义明确的机制合成，容易形成覆盖大面积的纤维网络，并且可以针对不同的功能进行设计。在这项工作中，细菌生物膜被设计成导电生物聚合物，与电极连接，并将细菌种群连接到电子产品。细菌生物膜被设计成具有不同的导电肽基序，因为已经提出融合肽基序的芳香族氨基酸含量通过影响单体堆积行为来贡献电子导电性。为了选择用于构建导电肽基序的最佳候选物，使用两种不同的纤维支架测量芳香族氨基酸的导电性能，淀粉样纤维（ALF）形成肽和CsgA蛋白的淀粉样蛋白生成R5T肽。芳香族氨基酸的三个重复被添加到纤维形成肽序列中，以产生类似于在导电聚合物中观察到的离域PI云。基于测量，酪氨酸和色氨酸残基提供最高的电导率。因此，非导电E.大肠杆菌生物膜通过基因插入的含有酪氨酸和色氨酸的不同组合的导电肽基序转换成导电形式。最后，使用受控的生物膜生产，用导电肽基序实现合成的生物膜生物发生。在活细胞上形成导电生物膜用于生物电子学和生物传感应用。
Bacterial biofilms are promising tools for functional applications as bionanomaterials. They are synthesized by well-defined machinery, readily form fiber networks covering large areas, and can be engineered for different functionalities. In this work, bacterial biofilms have been engineered for use as conductive biopolymers to interface with electrodes and connect bacterial populations to electronic gadgets. Bacterial biofilms are designed with different conductive peptide motifs, as the aromatic amino acid content of fused peptide motifs has been suggested to contribute to electronic conductivity by influencing monomer stacking behavior. To select the best candidates for constructing conductive peptide motifs, conductivity properties of aromatic amino acids are measured using two different fiber scaffolds, an amyloid-like fiber (ALF) forming peptide, and the amyloidogenic R5T peptide of CsgA protein. Three repeats of aromatic amino acids are added to fiber-forming peptide sequences to produce delocalized pi clouds similar to those observed in conductive polymers. Based on the measurements, tyrosine and tryptophan residues provide the highest conductivity. Therefore, the nonconductive E. coli biofilm is switched into a conductive form by genetically inserted conductive peptide motifs containing different combinations of tyrosine and tryptophan. Finally, synthetic biofilm biogenesis is achieved with conductive peptide motifs using controlled biofilm production. Conductive biofilms on living cells are formed for bioelectronics and biosensing applications.