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1.
Angew Chem Int Ed Engl ; 58(17): 5572-5576, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30801929

RESUMO

Multiple-enzyme-involving cascade reactions that yield bioenergy are necessary in natural oxidative phosphorylation. However, in vitro applications are hampered by the sensitivity of catalytic activity to environmental adaptation. Herein, we explore nanozyme-catalyzed cascade reactions in an assembled hybrid architecture for mitochondria-mimicking oxidative phosphorylation. Hollow silica microspheres containing trapped gold nanoparticles were synthesized to promote two enzyme-like catalytic reactions that transform glucose into gluconic acid in the presence of oxygen. The resulting transmembrane proton gradient drives natural ATP synthase reconstituted on the surface to convert ADP and inorganic phosphate into ATP. The assembled architecture possesses high activity for oxidative phosphorylation, comparable to that of natural mitochondria. This study provides a new natural-artificial hybrid prototype for exploring bioenergy supply systems and holds great promise for ATP-powered bioapplications.

2.
J Colloid Interface Sci ; 535: 325-330, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30316119

RESUMO

At present, photophosphorylation in natural or artificial systems is accomplished by the production of protons or their pumping across the biomembranes. Herein, different from this strategy above, we demonstrate a designed system which can effectively enhance photophosphorylation by photo-induced proton-scavenging through molecular assembly. Upon the introduction of photobase generators, a (photo-) chemical reaction occurs to produce hydroxyl ions. Accompanying the further extramembranous acid-base neutralization reaction, an outbound flow of protons is generated to drive the reconstituted adenosine triphosphate (ATP) synthase to produce ATP. That is, contrary to biochemistry, the proton gradient to drive photophosphorylation derives from the scavenging of protons present in the external medium by hydroxyl ions, produced by the partially photo-induced splitting of photobase generator. Such assembled system holds great potential in ATP-consuming bioapplications.


Assuntos
Complexos de ATP Sintetase/metabolismo , Trifosfato de Adenosina/biossíntese , Hidróxidos/síntese química , Nanoestruturas/química , Prótons , Trifosfato de Adenosina/química , Hidróxidos/química , Tamanho da Partícula , Fosforilação , Processos Fotoquímicos , Propriedades de Superfície
3.
Angew Chem Int Ed Engl ; 58(4): 1110-1114, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30517771

RESUMO

A proton gradient across a lipid membrane is required for the production of biochemical fuel. Much effort has been devoted to reactions involving proton production in biomimetic assembled architectures under mild conditions. Herein, we explored thiol-based self-assembled monolayer chemistry on a naked gold surface for the production of biochemical fuel. Protons are generated when alkanethiols self-assemble on a gold surface, and the proton yield can be tuned by the choice of thiol and by variation of the procedure used for the deposition of gold. Consequently, the proton gradient across a lipid membrane above the gold surface can be modulated to vary the production rate of biochemical fuel performed by lipid-embedded motor proteins. Our work presents evidence that a simple and efficient abiotic chemical reaction in a well-defined biohybrid system can convert unnatural chemicals, namely alkanethiols, into bioenergy molecules, a finding that has a great potential in biofuel-driven catalysis and devices.

4.
Angew Chem Int Ed Engl ; 57(22): 6532-6535, 2018 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-29655302

RESUMO

A natural-artificial hybrid system was constructed to enhance photophosphorylation. The system comprises chloroplasts modified with optically matched quantum dots (chloroplast-QD) with a large Stokes shift. The QDs possess a unique optical property and transform ultraviolet light into available and highly effective red light for use by chloroplasts. This favorable feature enables photosystem II contained within the hybrid system to split more water and produce more protons than chloroplasts would otherwise do on their own. Consequently, a larger proton gradient is generated and photophosphorylation is improved. At optimal efficiency activity increased by up to 2.3 times compared to pristine chloroplasts. Importantly, the degree of overlap between emission of the QDs and absorption of chloroplasts exerts a strong influence on the photophosphorylation efficiency. The chloroplast-QD hybrid presents an efficient solar energy conversion route, which involves a rational combination of a natural system and an artificial light-harvesting nanomaterial.


Assuntos
Trifosfato de Adenosina/biossíntese , Cloroplastos/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Pontos Quânticos/metabolismo , Semicondutores , Trifosfato de Adenosina/química , Cloroplastos/química , Luz , Fenômenos Ópticos , Fosforilação , Processos Fotoquímicos , Complexo de Proteína do Fotossistema II/química , Pontos Quânticos/química
5.
ACS Nano ; 12(2): 1455-1461, 2018 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-29361225

RESUMO

Plant thylakoids have a typical stacking structure, which is the site of photosynthesis, including light-harvesting, water-splitting, and adenosine triphosphate (ATP) production. This stacking structure plays a key role in exchange of substances with extremely high efficiency and minimum energy consumption through photosynthesis. Herein we report an artificially designed honeycomb multilayer for photophosphorylation. To mimic the natural thylakoid stacking structure, the multilayered photosystem II (PSII)-ATP synthase-liposome system is fabricated via layer-by-layer (LbL) assembly, allowing the three-dimensional distributions of PSII and ATP synthase. Under light illumination, PSII splits water into protons and generates a proton gradient for ATP synthase to produce ATP. Moreover, it is found that the ATP production is extremely associated with the numbers of PSII layers. With such a multilayer structure assembled via LbL, one can better understand the mechanism of PSII and ATP synthase integrated in one system, mimicking the photosynthetic grana structure. On the other hand, such an assembled system can be considered to improve the photophosphorylation.


Assuntos
Trifosfato de Adenosina/metabolismo , Materiais Biomiméticos/metabolismo , Lipossomos/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Plantas/metabolismo , Tilacoides/metabolismo , Materiais Biomiméticos/química , Lipossomos/química , ATPases Mitocondriais Próton-Translocadoras/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Fotofosforilação , Complexo de Proteína do Fotossistema II/química , Plantas/química , Prótons , Tilacoides/química
6.
ACS Nano ; 12(2): 1934-1939, 2018 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-29337528

RESUMO

Controlled growth of one-dimensional nanostructures is playing a key role in creating types of materials for functional devices. Here, we report procedures for controlled assembly of the dipeptide diphenylalanine (FF) into aligned and ultralong single crystals in a capillary. With the evaporation of solvent, nucleation of the crystal occurred in the confined region, and the crystal grew continuously with a supply of molecules from the concentration gradient system inside the capillary. Based on the "Knudsen regime", an ultralong aligned individual FF single crystal possessing an active optical waveguide property at macroscopic length scale could be obtained. Moreover, capillary is also an effective microdevice to investigate the disassembly process of the FF single crystals. This strategy has potentials to broaden the range of applications of aligned organic nanomaterials.


Assuntos
Cristalização/instrumentação , Fenilalanina/análogos & derivados , Cristalização/métodos , Cristalografia por Raios X/instrumentação , Cristalografia por Raios X/métodos , Desenho de Equipamento , Lasers , Fenilalanina/química , Solventes/química
7.
Angew Chem Int Ed Engl ; 57(7): 1903-1907, 2018 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-29280315

RESUMO

Tunable supramolecular assembly has found various applications in biomedicine, molecular catalysis, optoelectronics, and nanofabrication. Unlike traditional covalent conjugation, non-covalent introduction of a photoswitchable moiety enables reversible photomodulation of non-photosensitive dipeptide supramolecular assembly. Under light illumination, a long-lived photoacid generator releases a proton and mediates the dissociation of dipeptide-based organogel, thereby resulting in sol formation. Under darkness, the photoswitchable moiety entraps a proton, resulting in gel regeneration. Furthermore, accompanying the isothermal recycled gel-sol transition in a spatially controlled manner, renewable patterns are spontaneously fabricated. This new concept of light-controlled phase transition of amino acid-based supramolecular assemblies will open up the possibility of wide applications.

8.
ACS Nano ; 11(10): 10175-10183, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-28933821

RESUMO

Molecule assembly and functionalization of protocells have achieved a great success. However, the yield efficiency of photophosphorylation in the present cell-like systems is limited. Herein, inspired by natural photobacteria, we construct a protocell membrane reconstituting motor protein for highly efficient light-mediated adenosine triphosphate (ATP) synthesis through a layer-by-layer technique. The assembled membrane, compartmentally integrating photoacid generator, proton conductor, and ATP synthase, possesses excellent transparency, fast proton production, and quick proton transportation. Remarkably, these favorable features permit the formation of a large proton gradient in a confined region to drive ATP synthase to produce ATP with high efficiency (873 ATP s-1). It is the highest among the existing artificial photophosphorylation systems. Such a biomimetic system provides a bioenergy-supplying scenario for early photosynthetic life and holds promise in remotely controlled ATP-consumed biosensors, biocatalysts, and biodevices.


Assuntos
Membrana Celular/metabolismo , Proteínas Motores Moleculares/metabolismo , Complexos de ATP Sintetase/isolamento & purificação , Complexos de ATP Sintetase/metabolismo , Trifosfato de Adenosina/biossíntese , Trifosfato de Adenosina/química , Membrana Celular/química , Grafite/química , Grafite/metabolismo , Concentração de Íons de Hidrogênio , Proteínas Motores Moleculares/química , Estrutura Molecular , Tamanho da Partícula , Fosforilação , Processos Fotoquímicos , Propriedades de Superfície
9.
Angew Chem Int Ed Engl ; 56(42): 12903-12907, 2017 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-28834071

RESUMO

Enhancing solar energy conversion efficiency is very important for developing renewable energy, protecting the environment, and producing agricultural products. Efficient enhancement of photophosphorylation is demonstrated by coupling artificial photoacid generators (PAGs) with chloroplasts. The encapsulation of small molecular long-lived PAGs in the thylakoid lumen is improved greatly by ultrasonication. Under visible-light irradiation, a fast intramolecular photoreaction of the PAG occurs and produces many protons, remarkably enhancing the proton gradient in situ. Consequently, compared to pure chloroplasts, the assembled natural-artificial hybrid demonstrates approximately 3.9 times greater adenosine triphosphate (ATP) production. This work will provide new opportunities for constructing enhanced solar energy conversion systems.


Assuntos
Trifosfato de Adenosina/metabolismo , Cloroplastos/metabolismo , Benzopiranos/química , Benzopiranos/metabolismo , Indóis/química , Indóis/metabolismo , Luz , Microscopia Confocal , Nitrocompostos/química , Nitrocompostos/metabolismo , Fotofosforilação , Energia Solar
10.
Nanoscale ; 7(25): 10908-11, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26055965

RESUMO

A new type of biohybrid photo-electrochemical cell was fabricated by layer-by-layer assembly of photosystem II and reduced graphene oxide. We demonstrate that the photocurrent in the direct electron transfer is enhanced about two fold with improved stability. The assembly strategy without any cross-linker or additional electron mediators makes the cell fabrication and operation much simpler as compared to previous approaches. This work may open new routes for the construction of solar energy conversion systems based on photoactive proteins and graphene materials.

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