Thioflavin T‐Amyloid Hybrid Nanostructure for Biocatalytic Photosynthesis

Abstract

Amyloidogenic peptides can self-assemble into highly ordered nanostructures consisting of cross β-sheet-rich networks that exhibit unique physicochemical properties and high stability. Light-harvesting amyloid nanofibrils are constructed by employing insulin as a building block and thioflavin T (ThT) as a amyloid-specific photosensitizer. The ability of the self-assembled amyloid scaffold to accommodate and align ThT in high density on its surface allows for efficient energy transfer from the chromophores to the catalytic units in a similar way to natural photosystems. Insulin nanofibrils significantly enhance the photoactivity of ThT by inhibiting nonradiative conformational relaxation around the central CC bonds and narrowing the distance between ThT molecules that are bound to the β-sheet-rich amyloid structure. It is demonstrated that the ThT-amyloid hybrid nanostructure is suitable for biocatalytic solar-to-chemical conversion by integrating the light-harvesting amyloid module (for nicotinamide cofactor regeneration) with a redox biocatalytic module (for enzymatic reduction).

Bioinspired NADH Regeneration Based on Conjugated Photocatalytic Systems

“…[ 47 ] Besides the commonly used eosin Y, [ 48 ] thioflavin, as a molecular photosensitizer, also showed potential for NADH regeneration. [ 49 ]…”

Double-Stranded DNA Matrix for Photosensitization Switching

“…[30][31][32] However, the oscillator strength of SG at 90°is nearly zero, which is not feasible for the whole transition. Therefore, D-A separation may be a design principle for highly efficient PSs (different from the quasi-plane structure requirement of fluorescence), but the oscillator strength should also be taken into consideration (e.g., TICT-based PSs 38,39 ). Here, the activated S 1 of SG after binding with dsDNA may be a compromise between ISC and oscillator strength, again confirming the unique role of the dsDNA matrix in the photosensitization activation of SG (Scheme 1).…”

Photo-Biocatalysis: Biotransformations in the Presence of Light

“…The most straightforward approach for such systems is the use of photochemical reactions to reduce (recycle) the cofactors NAD­(P)­H or FMNH 2 , which are subsequently used in a biocatalytic reaction. − …”