TY - JOUR
T1 - Proton-Conductive Melanin-Like Fibers through Enzymatic Oxidation of a Self-Assembling Peptide
AU - Reddy, Samala Murali Mohan
AU - Raßlenberg, Eileen
AU - Sloan-Dennison, Sian
AU - Hesketh, Travis
AU - Silberbush, Ohad
AU - Tuttle, Tell
AU - Smith, Ewen
AU - Graham, Duncan
AU - Faulds, Karen
AU - Ulijn, Rein V.
AU - Ashkenasy, Nurit
AU - Lampel, Ayala
N1 - Funding Information:
S.M.M.R. and E.R. contributed equally to this work. This research was supported by the U.S. Air Force Office of Scientific Research (grant FA9550-19-1-0111) and by the Israel Science Foundation (grant No. 375/18). S.M.M.R. is a recipient of the BGU Kreitman School for post-doctorate fellowship. The authors thank O. Abarbanel, S. Panettieri, and Y. He (Live Imaging Facility at the Advanced Science Research Center, The Graduate Center CUNY) and S. A. McPhee (Nanoscience Initiative, ASRC, CUNY) for the help with the SHG imaging and LCMS analysis. Devices were fabricated at the Unit for Nanofabrication at the Hebrew University of Jerusalem.
Funding Information:
S.M.M.R. and E.R. contributed equally to this work. This research was supported by the U.S. Air Force Office of Scientific Research (grant FA9550‐19‐1‐0111) and by the Israel Science Foundation (grant No. 375/18). S.M.M.R. is a recipient of the BGU Kreitman School for post‐doctorate fellowship. The authors thank O. Abarbanel, S. Panettieri, and Y. He (Live Imaging Facility at the Advanced Science Research Center, The Graduate Center CUNY) and S. A. McPhee (Nanoscience Initiative, ASRC, CUNY) for the help with the SHG imaging and LCMS analysis. Devices were fabricated at the Unit for Nanofabrication at the Hebrew University of Jerusalem.
Publisher Copyright:
© 2020 Wiley-VCH GmbH
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Melanin pigments have various properties that are of technological interest including photo- and radiation protection, rich coloration, and electronic functions. Nevertheless, laboratory-based synthesis of melanin and melanin-like materials with morphologies and chemical structures that are specifically optimized for these applications, is currently not possible. Here, melanin-like materials that are produced by enzymatic oxidation of a supramolecular tripeptide structures that are rich in tyrosine and have a 1D morphology are demonstrated, that are retained during the oxidation process while conducting tracks form through oxidative tyrosine crosslinking. Specifically, a minimalistic self-assembling peptide, Lys–Tyr–Tyr (KYY) with strong propensity to form supramolecular fibers, is utilized. Analysis by Raman spectroscopy shows that the tyrosines are pre-organized inside these fibers and, upon enzymatic oxidation, result in connected catechols. These form 1D conducting tracks along the length of the fiber, which gives rise to a level of internal disorder, but retention of the fiber morphology. This results in highly conductive structures demonstrated to be dominated by proton conduction. This work demonstrates the ability to control oxidation but retain a well-defined fibrous morphology that does not have a known equivalent in biology, and demonstrate exceptional conductivity that is enhanced by enzymatic oxidation.
AB - Melanin pigments have various properties that are of technological interest including photo- and radiation protection, rich coloration, and electronic functions. Nevertheless, laboratory-based synthesis of melanin and melanin-like materials with morphologies and chemical structures that are specifically optimized for these applications, is currently not possible. Here, melanin-like materials that are produced by enzymatic oxidation of a supramolecular tripeptide structures that are rich in tyrosine and have a 1D morphology are demonstrated, that are retained during the oxidation process while conducting tracks form through oxidative tyrosine crosslinking. Specifically, a minimalistic self-assembling peptide, Lys–Tyr–Tyr (KYY) with strong propensity to form supramolecular fibers, is utilized. Analysis by Raman spectroscopy shows that the tyrosines are pre-organized inside these fibers and, upon enzymatic oxidation, result in connected catechols. These form 1D conducting tracks along the length of the fiber, which gives rise to a level of internal disorder, but retention of the fiber morphology. This results in highly conductive structures demonstrated to be dominated by proton conduction. This work demonstrates the ability to control oxidation but retain a well-defined fibrous morphology that does not have a known equivalent in biology, and demonstrate exceptional conductivity that is enhanced by enzymatic oxidation.
KW - melanin
KW - peptides
KW - proton conduction
KW - self-assembly
KW - supramolecular materials
UR - http://www.scopus.com/inward/record.url?scp=85092466255&partnerID=8YFLogxK
U2 - 10.1002/adma.202003511
DO - 10.1002/adma.202003511
M3 - Article
C2 - 33058283
AN - SCOPUS:85092466255
SN - 0935-9648
VL - 32
JO - Advanced Materials
JF - Advanced Materials
IS - 46
M1 - 2003511
ER -