Researchers at Berkeley have been developing a hybrid polymer-protein material that, when stress is introduced into the polymer component, changes the fluorescing properties of the protein structure. By bridging biology and material science at the biochemical level, this research may lead to interesting sensor applications in medicine and the development of materials having inherent reporting abilities.
In their work, the scientists combined the structural properties of the thermosome (THS), a chaperonin (protein complex) from the thermophilic organism Thermoplasma acidophilum, with the spectral properties of fluorescent proteins to generate a protein complex that exhibits fluorescence resonance energy transfer (FRET) and is sensitive to structural deformation.
"Our concept for a THS-based stress sensor is based on the idea that guest proteins can be permanently entrapped into the cavities by covalent linker chemistry," writes Clark. "Entrapping a donor–acceptor pair of fluorescent proteins into the cavities gives the possibility for FRET to occur. The centers of the two cavities are approximately 7 nm apart, which is close to the Förster radius (4.9 nm) of enhanced cyan fluorescent protein (eCFP) and enhanced yellow fluorescent protein (eYFP), which are the most commonly used donor–acceptor FRET pair in molecular biology. We thus hypothesized that, by covalently crosslinking chains of a polymer matrix with the THS–guest complex, a sufficient force applied to the matrix will separate the two halves of the THS, which results in reduced FRET."
The coupling between the modified THS and the modified fluorescent proteins was carried out by simple incubation of a mixture of the proteins for several hours at room temperature in a coupling buffer. Subsequent fluorescence spectroscopy measurements proved that FRET occurs between the fluorescent proteins.
Read on at Nanowerk…
Abstract in Angewandte Chemie: Mechanical Nanosensor Based on FRET within a Thermosome: Damage-Reporting Polymeric Materials…
Clark Lab…
