Peptides as Bio-inspired Molecular Electronic Materials
Understanding the electronic properties of single peptides is not only of fundamental importance to biology, but it is also pivotal to the realization of bio-inspired molecular electronic materials. Natural proteins have evolved to promote electron transfer in many crucial biological processes. However, their complex conformational nature inhibits a thorough investigation, so in order to study electron transfer in proteins, simple peptide models containing redox active moieties present as ideal candidates. Here we highlight the importance of secondary structure characteristic to proteins/peptides, and its relevance to electron transfer. The proposed mechanisms responsible for such transfer are discussed, as are details of the electrochemical techniques used to investigate their electronic properties. Several factors that have been shown to influence electron transfer in peptides are also considered. Finally, a comprehensive experimental and theoretical study demonstrates that the electron transfer kinetics of peptides can be successfully fine tuned through manipulation of chemical composition and backbone rigidity. The methods used to characterize the conformation of all peptides synthesized throughout the study are outlined, along with the various approaches used to further constrain the peptides into their geometric conformations. The aforementioned sheds light on the potential of peptides to one day play an important role in the fledgling field of molecular electronics.
KeywordsPeptides Electron transfer Bio-inspired Molecular electronics Electronic materials Electrochemical methods
This work is supported by the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP). The authors also gratefully acknowledge the assistance of the Australian National Fabrication Facility (ANFF).
- Bard AJ, Faulkner LR (2000) Electrochemical methods: fundamentals and applications, 2nd edn. Wiley, New YorkGoogle Scholar
- Bendall DS (1996) Protein electron transfer. BIOS Scientific Publishers, OxfordGoogle Scholar
- Emanuelsson R, Löfås H, Wallner A, Nauroozi D, Baumgartner J, Marschner C, Ahuja R, Ott S, Grigoriev A, Ottosson H (2014) Configuration and conformation-dependent electronic structure variations in 1,4-disubstituted cyclohexanes enabled by a carbon-to-silicon exchange. Chem Eur J 20(30):9304–9311PubMedCrossRefGoogle Scholar
- Gatto E, Porchetta A, Scarselli M, De Crescenzi M, Formaggio F, Toniolo C, Venanzi M (2012) Playing with peptides: how to build a supramolecular peptide nanostructure by exploiting helix center dot center dot center dot helix macrodipole interactions. Langmuir 28(5):2817–2826PubMedCrossRefGoogle Scholar
- Hermanson GT (2008) Bioconjugate techniques, 2nd edn. Academic, LondonGoogle Scholar
- Laviron E (1979) The use of linear potential sweep voltammetry and of a.c. voltammetry for the study of the surface electrochemical reaction of strongly adsorbed systems and of redox modified electrodes. J Electroanal Chem 100:263Google Scholar
- Marques-Gonzalez S, Yufit DS, Howard JAK, Martin S, Osorio HM, Garcia-Suarez VM, Nichols RJ, Higgins SJ, Cea P, Low PJ (2013) Simplifying the conductance profiles of molecular junctions: the use of the trimethylsilylethynyl moiety as a molecule-gold contact. Dalton T 42(2):338–341CrossRefGoogle Scholar
- Neuhaus DE, P. A (1993) Methods in molecular biology, vol 17. Humana Press, CliftonGoogle Scholar
- Petrov EG, Shevchenko YV, May V (2003) On the length dependence of bridge-mediated electron transfer reactions. Elsevier 288:269–279Google Scholar
- Seyedsayamdost MR, Yee CS, Reece SY, Nocera DG, Stubbe J (2006) pH rate profiles of FnY356−R2s (n = 2, 3, 4) in Escherichia coli ribonucleotide reductase: evidence that Y356 is a redox-active amino acid along the radical propagation pathway. J Am Chem Soc 128(5):1562–1568PubMedCrossRefGoogle Scholar
- Toniolo C, Benedetti E (1991) The polypeptide 310-helix. Trends Biochem Sci 16(0):350–353Google Scholar