Interference of Solvatochromic Twist in Amyloid Nanostructure for Light-Driven Biocatalysis

Abstract

Amyloid self-assembly is a powerful bottom-up approach for the synthesis of sophisticated organic nanostructures that possess fascinating structural flexibility. This study adds a dimension to the research on amyloid self-assembly by expanding its scope to the field of photobiocatalysis. We demonstrate visible-light-driven regeneration of nicotinamide adenine dinucleotide (NAD+) using solvatochromic Congo red (CR) hybridized with an amyloid-derived peptide (Fmoc-FF) nanostructure. In the course of an in situ self-assembly process of Fmoc-FF peptides, CR molecules were hybridized into a Fmoc-FF nanofiber network through π–π interactions between the nonpolar fluorenyl group of Fmoc-FF and the aromatic moieties of CR. This hybridization made CR dyes capable of photoredox catalysis because the planarization of CR induced by the Fmoc-FF degenerated the twisted intramolecular charge-transfer state of the dye; the incorporation of CR into the Fmoc-FF nanostructure increased CR’s fluorescence intensity 9 times and generated a photocurrent by 400 nA cm–2. The photocatalytic Fmoc-FF/CR hydrogel facilitated O2 reduction-coupled NAD+ regeneration under visible light. The NAD+ regeneration yield of the Fmoc-FF/CR hybrid was 5 times higher than that of free CR. Furthermore, the in situ regenerated NAD+ activated NAD+-dependent redox enzymes for alcohol oxidation; the Fmoc-FF/CR hybrid achieved a substantially high total turnover number of enzymes of 42 953, which was 5.8 times larger than that with free CR.

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).…”

Construction of Thiazolo[5,4-d]thiazole-based Two-Dimensional Network for Efficient Photocatalytic CO2 Reduction

“…Given the conjugated and porous structure, the photocatalytic activities for NADH regeneration of TZTZ-TP and TZTZ-TA were further examined (Scheme ). Oxidoreductases play important roles in metabolic processes and a lot of industrially important enzymes depend upon NAD­(P)H cofactors. − In addition, NADH has also been used for CO 2 reduction and useful synthetically redox reactions. ,− However, the high price of NADH makes it difficult to be consumed in stoichiometric amounts. Extensive efforts have been made to develop efficient methods for NADH regeneration from the oxidized counterpart with inexpensive reducing equivalents during the past 10 years. − Herein, the as-prepared TZTZ -based CMPs were employed as the photocatalyst for solar-driven NADH regeneration with [Cp*Rh­(bpy)­(H)] + ( M , in abbreviation) acting as an electron mediator and a hydride transfer agent and TEOA as an electron donor (Scheme ).…”

Light-Driven Catalytic Regulation of Enzymes at the Interface with Plasmonic Nanomaterials

“…The combination of enzymes and materials with photochromic functionality is usually exploited for this aim. The most common approach comprises mixing soluble enzymes and photoactive materials in one pot, which couples a photocatalytic step with a biocatalytic one . Whereas the enzymes consume the redox cofactor to perform the reaction of interest, the light-irradiated material replenishes the pool of the cofactor demanded by the enzyme.…”

“…The most common approach comprises mixing soluble enzymes and photoactive materials in one pot, which couples a photocatalytic step with a biocatalytic one. 50 Whereas the enzymes consume the redox cofactor to perform the reaction of interest, the light-irradiated material replenishes the pool of the cofactor demanded by the enzyme. A similar strategy has been recently adopted for the photocatalytic in situ production of H 2 O 2 employed by peroxygenases.…”