Microbial nanowires
View Patent ↗The application describes electrically conductive nanowires, as well as genetically and/or chemically modified nanowires with modified conductive, adhesive and/or coupling properties.
1. An isolated Geobacteraceae nanowire polypeptide which is genetically or chemically modified, wherein the polypeptide is a variant of a polypeptide of SEQ ID NO:9 or SEQ ID NO:10 and has at least 95% amino acid sequence identity to SEQ ID NO:9 or SEQ ID NO:10, the polypeptide modified by substitution, replacement or modification of amino acid(s) in the polypeptide and having modified electrical conductivity.
2. The nanowire polypeptide of claim 1 , wherein the polypeptide is genetically modified and does not have a sequence that is identical to SEQ ID NO:9 or SEQ ID NO:10.
3. The nanowire polypeptide of claim 1 , wherein at least one hydrophobic or apolar amino acid is replaced with a hydrophilic or aromatic amino acid.
4. The nanowire polypeptide of claim 1 , which has at least one amino acid replaced with a tyrosine or tryptophan residue.
5. The nanowire polypeptide of claim 1 , which has at least one amino acid replaced with an aspartic acid, a glutamic acid, a lysine or an arginine residue.
6. The nanowire polypeptide of claim 1 , wherein at least 50% of the secondary structure in the nanowire polypeptide is α-helical.
7. The nanowire polypeptide of claim 1 , wherein the nanowire polypeptide assembles into an electrically conductive pilus.
8. The nanowire polypeptide of claim 1 , wherein the nanowire polypeptide contains no metals.
9. The nanowire polypeptide of claim 1 , which is chemically modified to modulate the conductive, adhesive and/or coupling properties of the nanowire polypeptide.
10. The nanowire polypeptide of claim 1 , which is chemically modified using a reagent selected from performic acid, a peroxide, iodoacetamide, iodoacetic acid, bissulfosuccinimidyl suberate, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, N-ethylmaleimide, methyl methanethiosulfonate and S-(2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl methanesulfonothioate.
11. A nanowire polypeptide selected from Geobacteraceae, wherein the amino acid sequence is genetically or chemically modified, wherein the polypeptide is a variant of and has at least 95% amino acid sequence identity to a polypeptide sequence selected from SEQ ID NO:9 and SEQ ID NO:10, wherein the polypeptide is modified by substitution, replacement or modification of the amino acid(s), wherein the nanowire polypeptide has electrical conductivity activity that is less than 90% or greater than 120% of the electrical conductivity activity of polypeptides of SEQ ID NO:9 or SEQ ID NO:10.
12. A pilus comprising the nanowire polypeptide of claim 1 .
13. A mutated nanowire polypeptide comprising the amino acid sequence of SEQ ID NO: 9 or 10, wherein at least one hydrophobic or apolar amino acid selected from A11, I12, I13, I15, L16, A17, A18, I19, A20, I21, P22, A26, V29, A31, A35, A36, I40, L43, A46, L47, A50, A52, P58 and P59 is substituted or replaced with a hydrophilic or aromatic amino acid to modify electrical conductivity.
14. The mutated nanowire polypeptide of claim 13 , wherein the encoded polypeptide has at least one amino acid replaced with a tyrosine or a tryptophan residue.
15. The mutated nanowire polypeptide of claim 13 , wherein the encoded polypeptide has at least one amino acid replaced with an aspartic acid, a glutamic acid, a lysine or an arginine residue.
16. The mutated nanowire polypeptide of claim 13 , wherein the encoded polypeptide has at least 50% of the secondary structure of the polypeptide as an α-helix.
17. The mutated nanowire polypeptide of claim 13 , wherein the encoded polypeptide assembles into an electrically conductive pilus.
18. The nanowire polypeptide of claim 1 , wherein the polypeptide sequence is selected from SEQ ID NO:19-25.
19. The nanowire polypeptide of claim 1 wherein at least one hydrophobic or apolar amino acid selected from A11, I12, I13, I15, L16, A17, A18, I19, A20, I21, P22, A26, V29, A31, A35, A36, I40, L43, A46, L47, A50, A52, P58 and P59 is substituted or replaced with a hydrophilic or aromatic amino acid to modify electrical conductivity.
20. The nanowire polypeptide of claim 1 from Geobacter sulfurreducens.
21. The mutated nanowire polypeptide of claim 13 , wherein the polypeptide has at least 95% amino acid sequence identity to a polypeptide sequence selected from SEQ ID NO:9 and SEQ ID NO:10.
22. The mutated nanowire polypeptide of claim 13 wherein the polypeptide sequence is selected from SEQ ID NO:19-25.
23. The nanowire polypeptide of claim 13 , wherein the polypeptide is from Geobacter sulfurreducens.