Genetically encoded conductive protein nanofibers secreted by engineered cells
Date
2017-06Source Title
RSC Advances
Print ISSN
2046-2069
Publisher
Royal Society of Chemistry
Volume
7
Issue
52
Pages
32543 - 32551
Language
English
Type
ArticleItem Usage Stats
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Abstract
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 π clouds similar to those observed in conductive polymers. Based on the measurements, tyrosine and tryptophan residues provide the highest conductivity. Therefore, the non-conductive 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.
Keywords
Amino acidsAromatic compounds
Aromatic polymers
Aromatization
Biofilms
Biopolymers
Escherichia coli
Fibers
Machinery
Proteins
Scaffolds (biology)
Aromatic amino acid
Bacterial population
Biosensing applications
Conductive biofilms
Conductivity properties
Electronic conductivity
Functional applications
Tryptophan residues
Peptides