A Thermostable Protein Matrix for Spectroscopic Analysis of Organic Semiconductors
- 16 July 2020
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 142 (32), 13898-13907
- https://doi.org/10.1021/jacs.0c05477
Abstract
Advances in protein design and engineering have yielded peptide assemblies with enhanced and non-native functionalities. Here, various molecular organic semiconductors (OSCs), with known excitonic up- and down-conversion properties, are attached to a de novo-designed protein, conferring entirely novel functions on the peptide scaffolds. The protein-OSC complexes form similarly-sized, stable, water-soluble nanoparticles that are robust to cryogenic freezing and processing into the solid-state. The peptide matrix enables the formation of protein-OSC-trehalose glasses that fix the proteins in their folded states under oxygen-limited conditions. The encapsulation dramatically enhances the stability of protein-OSC complexes to photo-damage, increasing the lifetime of the chromophores from several hours to more than 10 weeks under constant illumination. Comparison of the photophysical properties of astaxanthin aggregates in mixed-solvent systems and proteins shows that the peptide environment does not alter the underlying electronic processes of the incorporated materials, exemplified here by singlet exciton fission followed by separation into weakly-bound, localized triplets. The adaptable protein-based approach lays the foundation for spectroscopic assessment of a broad range of molecular OSCs in aqueous solutions and the solid-state, circumventing the laborious procedure of identifying the experimental conditions necessary for aggregate generation or film formation. The non-native protein functions also raise the prospect of future bio-compatible devices where peptide assemblies could complex with native and non-native systems to generate novel functional materials.Funding Information
- Division of Chemistry (CHE 1609974)
- Engineering and Physical Sciences Research Council (EP/M025330/1, EP/S002103/1)
- Office of the Royal Society (URF\R1\191548)
- University of Sheffield
- H2020 European Research Council (854126)
- Biotechnology and Biological Sciences Research Council (BB/M000265/1)
- Division of Materials Research (DMR-1810838)
This publication has 68 references indexed in Scilit:
- Upconversion nanoparticles and their composite nanostructures for biomedical imaging and cancer therapyNanoscale, 2012
- Engineering enzymesFaraday Discussions, 2010
- High-Yield Singlet Fission in a Zeaxanthin Aggregate Observed by Picosecond Resonance Raman SpectroscopyJournal of the American Chemical Society, 2010
- AutoDock4 and AutoDockTools4: Automated docking with selective receptor flexibilityJournal of Computational Chemistry, 2009
- Design and engineering of an O2 transport proteinNature, 2009
- Analysis of the UV/Vis and CD Spectral Line Shapes of Carotenoid Assemblies: Spectral Signatures of Chiral H-AggregatesJournal of the American Chemical Society, 2009
- Effect of trehalose on protein structureProtein Science, 2008
- Upconversion injection in rubrene/perylene-diimide-heterostructure electroluminescent diodesApplied Physics Letters, 2007
- Using circular dichroism collected as a function of temperature to determine the thermodynamics of protein unfolding and binding interactionsNature Protocols, 2006
- Self-Assembled Aggregates of the Carotenoid Zeaxanthin: Time-Resolved Study of Excited StatesThe Journal of Physical Chemistry A, 2005