428 results match your criteria photo enzymatic

Enzymatic degradation of polyethylene terephthalate nanoplastics analyzed in real time by isothermal titration calorimetry.

Sci Total Environ 2021 Jun 3;773:145111. Epub 2021 Feb 3.

Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, D-04318 Leipzig, Germany. Electronic address:

Plastics are globally used for a variety of benefits. As a consequence of poor recycling or reuse, improperly disposed plastic waste accumulates in terrestrial and aquatic ecosystems to a considerable extent. Large plastic waste items become fragmented to small particles through mechanical and (photo)chemical processes. Read More

View Article and Full-Text PDF

Methanol-Driven Oxidative Rearrangement of Biogenic Furans - Enzyme Cascades vs. Photobiocatalysis.

Front Chem 2021 7;9:635883. Epub 2021 Apr 7.

Department of Chemistry, Aalto University, Espoo, Finland.

The oxidative ring expansion of bio-derived furfuryl alcohols to densely functionalized six-membered O-heterocycles represents an attractive strategy in the growing network of valorization routes to synthetic building blocks out of the lignocellulosic biorefinery feed. In this study, two scenarios for the biocatalytic Achmatowicz-type rearrangement using methanol as terminal sacrificial reagent have been evaluated, comparing multienzymatic cascade designs with a photo-bio-coupled activation pathway. Read More

View Article and Full-Text PDF

A MnO nanosheet-mediated photo-controlled DNAzyme for intracellular miRNA cleavage to suppress cell growth.

Analyst 2021 Apr 20. Epub 2021 Apr 20.

State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha, P. R. China.

Certain miRNAs, called oncomiRs, play a causal role in the onset and maintenance of cancer when overexpressed, thus, representing a potential new class of targets for therapeutic intervention. RNA-cleaving DNAzymes, mainly aimed at mRNA, have shown potential as therapeutic agents for various diseases. However, it's rarely reported that a DNAzyme was used for intracellular miRNA cleavage to suppress cell growth. Read More

View Article and Full-Text PDF

Evaluation of a Model Photo-Caged Dehydropeptide as a Stimuli-Responsive Supramolecular Hydrogel.

Nanomaterials (Basel) 2021 Mar 11;11(3). Epub 2021 Mar 11.

Center of Chemistry, University of Minho, 4710-057 Braga, Portugal.

Short peptides capped on the -terminus with aromatic groups are often able to form supramolecular hydrogels, via self-assembly, in aqueous media. The rheological properties of these readily tunable hydrogels resemble those of the extracellular matrix (ECM) and therefore have potential for various biological applications, such as tissue engineering, biosensors, 3D bioprinting, drug delivery systems and wound dressings. We herein report a new photo-responsive supramolecular hydrogel based on a "caged" dehydropeptide (CNB-Phe-ΔPhe-OH ), containing a photo-cleavable carboxy-2-nitrobenzyl (CNB) group. Read More

View Article and Full-Text PDF

Making ATRP More Practical: Oxygen Tolerance.

Acc Chem Res 2021 04 22;54(7):1779-1790. Epub 2021 Mar 22.

Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States.

Atom-transfer radical polymerization (ATRP) is a well-known technique for the controlled polymerization of vinyl monomers under mild conditions. However, as with any other radical polymerization, ATRP typically requires rigorous oxygen exclusion, making it time-consuming and challenging to use by nonexperts. In this Account, we discuss various approaches to achieving oxygen tolerance in ATRP, presenting the overall progress in the field. Read More

View Article and Full-Text PDF

Making waves: Microbe-photocatalyst hybrids may provide new opportunities for treating heavy metal polluted wastewater.

Water Res 2021 May 27;195:116984. Epub 2021 Feb 27.

College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, People's Republic of China; School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, People's Republic of China. Electronic address:

Heavy metal contamination has received increasing attention as a growing worldwide environmental problem. Traditional remediation methods are mainly based on adsorption, precipitation and oxidation-reduction, which reduce the availability or toxicity of heavy metal ions. Microbe-photocatalyst hybrids (MPH), which behave as a semi-artificial photosynthetic system, integrate microbial cells with artificial photocatalysts for solar-to-chemical conversion. Read More

View Article and Full-Text PDF

Remediation of emerging environmental pollutants: A review based on advances in the uses of eco-friendly biofabricated nanomaterials.

Chemosphere 2021 Jul 15;275:129975. Epub 2021 Feb 15.

Laboratory of Plant Healthcare and Diagnostics, PG Department of Biotechnology and Microbiology, Karnataka University, Dharwad, 580 003, Karnataka, India. Electronic address:

The increased environmental pollutants due to anthropogenic activities are posing an adverse effects and threat on various biotic forms on the planet. Heavy metals and certain organic pollutants by their toxic persistence in the environment are regarded as significant pollutants worldwide. In recent years, pollutants exist in various forms in the environment are difficult to eliminate by traditional technologies due to various drawbacks. Read More

View Article and Full-Text PDF

Formation of protein cross-links by singlet oxygen-mediated disulfide oxidation.

Redox Biol 2021 May 23;41:101874. Epub 2021 Jan 23.

Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark. Electronic address:

Cross-links formed within and between proteins are a major cause of protein dysfunction, and are postulated to drive the accumulation of protein aggregates in some human pathologies. Cross-links can be formed from multiple residues and can be reversible (usually sulfur-sulfur bonds) or irreversible (typically carbon-carbon or carbon-heteroatom bonds). Disulfides formed from oxidation of two Cys residues are widespread, with these formed both deliberately, via enzymatic reactions, or as a result of unintended oxidation reactions. Read More

View Article and Full-Text PDF

Chromoselective Photocatalysis Enables Stereocomplementary Biocatalytic Pathways*.

Angew Chem Int Ed Engl 2021 03 26;60(13):6965-6969. Epub 2021 Feb 26.

Institute of Chemistry, Department of Organic and Bioorganic Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, Heinrichstrasse 28, 8010, Graz, Austria.

Controlling the selectivity of a chemical reaction with external stimuli is common in thermal processes, but rare in visible-light photocatalysis. Here we show that the redox potential of a carbon nitride photocatalyst (CN-OA-m) can be tuned by changing the irradiation wavelength to generate electron holes with different oxidation potentials. This tuning was the key to realizing photo-chemo-enzymatic cascades that give either the (S)- or the (R)-enantiomer of phenylethanol. Read More

View Article and Full-Text PDF

Degradation of Antibiotics in Wastewater: New Advances in Cavitational Treatments.

Molecules 2021 Jan 25;26(3). Epub 2021 Jan 25.

Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via P. Giuria 9, 10125 Turin, Italy.

Over the past few decades, antibiotics have been considered emerging pollutants due to their persistence in aquatic ecosystems. Even at low concentrations, these pollutants contribute to the phenomenon of antibiotic resistance, while their degradation is still a longstanding challenge for wastewater treatment. In the present literature survey, we review the recent advances in synergistic techniques for antibiotic degradation in wastewater that combine either ultrasound (US) or hydrodynamic cavitation (HC) and oxidative, photo-catalytic, and enzymatic strategies. Read More

View Article and Full-Text PDF
January 2021

Effect of Spacer Length in Pyrene-Modified-Phenylboronic Acid Probe/CyD Complexes on Fluorescence-based Recognition of Monosaccharides in Aqueous Solution.

Anal Sci 2021 May 15;37(5):721-726. Epub 2021 Jan 15.

Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University.

The chemical sensing of saccharides is of importance for the diagnosis of diabetes. Various enzymatic sensors have been developed, but their heat and pH instability issues need to be resolved. In this regard, the development of artificial saccharide sensors with high stability is attracting attention. Read More

View Article and Full-Text PDF

Enhancing Resistance of Silk Fibroin Material to Enzymatic Degradation by Cross-Linking Both Crystalline and Amorphous Domains.

ACS Biomater Sci Eng 2020 04 3;6(4):2459-2468. Epub 2020 Mar 3.

Ear Science Institute Australia; Subiaco, Australia and Ear Sciences Centre, Faculty of Health and Medical Sciences, The University of Western Australia, Nedlands 6009, Australia.

Silk fibroin (SF) membranes are finding widespread use as biomaterial scaffolds in a range of tissue engineering applications. The control over SF scaffold degradation kinetics is usually driven by the proportion of SF crystalline domains in the formulation, but membranes with a high β-sheet content are brittle and still contain amorphous domains, which are highly susceptible to enzymatic degradation. In this work, photo-cross-linking of SF using a ruthenium-based method, and with the addition of glycerol, was used to generate robust and flexible SF membranes for long-term tissue engineering applications requiring slow degradation of the scaffolds. Read More

View Article and Full-Text PDF

Effects of Soil Tillage, Management Practices, and Mulching Film Application on Soil Health and Peanut Yield in a Continuous Cropping System.

Front Microbiol 2020 23;11:570924. Epub 2020 Dec 23.

State Key Laboratory of Crop Biology, Agronomy College of Shandong Agricultural University, Tai'an, China.

Our objective was to optimize soil management practices to improve soil health to increase peanut ( L.) yield. We studied the effects of using rotary tillage with mulching film or without [rotary tillage with no mulching (RTNM)], plow tillage with mulching film or without, and green manure with mulching film (GMMF) or without [green manure with no mulching (GMNM)] over 3 years in Tai'an, China. Read More

View Article and Full-Text PDF
December 2020

Dual catalytic cascaded nanoplatform for photo/chemodynamic/starvation synergistic therapy.

Colloids Surf B Biointerfaces 2021 Mar 21;199:111538. Epub 2020 Dec 21.

School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China. Electronic address:

In this study, manganese dioxide (MnO) was attached to prussian blue (PB) by a one-pot method to prepare PBMO. Then, the GOD was loaded onto PBMO through the electrostatic interaction of hyaluronic acid (HA) to form tumor-targeted nanoplatform (PBMO-GH). Hydrogen peroxide (HO) and gluconic acid were produced through the GOD-catalyzed enzymatic reaction. Read More

View Article and Full-Text PDF

Photochemical Formation of Methylhydroperoxide in Dissolved Organic Matter Solutions.

Environ Sci Technol 2021 01 29;55(2):1076-1087. Epub 2020 Dec 29.

Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, P. R. China.

Although it is known that the solar irradiation of chromophoric dissolved organic matter (CDOM) solutions generates HO, whether or not organic hydroperoxides (ROOHs) are photochemically formed remains unclear. This study employs high-performance liquid chromatography with the postcolumn enzymatic derivatization method to examine whether ROOHs can be formed in CDOM solutions under simulated solar irradiation. Methylhydroperoxide (MHP) is the only identified ROOH under our experimental conditions, and the quantum yields of MHP (Φ) vary from (1. Read More

View Article and Full-Text PDF
January 2021

Gated Proton Release during Radical Transfer at the Subunit Interface of Ribonucleotide Reductase.

J Am Chem Soc 2021 01 23;143(1):176-183. Epub 2020 Dec 23.

Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States.

The class Ia ribonucleotide reductase of requires strict regulation of long-range radical transfer between two subunits, α and β, through a series of redox-active amino acids (Y•[β] ↔ W?[β] ↔ Y[β] ↔ Y[α] ↔ Y[α] ↔ C[α]). Nowhere is this more precarious than at the subunit interface. Here, we show that the oxidation of Y is regulated by proton release involving a specific residue, E[β], which is part of a water channel at the subunit interface for rapid proton transfer to the bulk solvent. Read More

View Article and Full-Text PDF
January 2021

Oxidation of protein disulfide bonds by singlet oxygen gives rise to glutathionylated proteins.

Redox Biol 2021 01 1;38:101822. Epub 2020 Dec 1.

Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark. Electronic address:

Disulfide bonds play a key function in determining the structure of proteins, and are the most strongly conserved compositional feature across proteomes. They are particularly common in extracellular environments, such as the extracellular matrix and plasma, and in proteins that have structural (e.g. Read More

View Article and Full-Text PDF
January 2021

β-Carboline-Based pH Fluorescent Probe and Its Application for Monitoring Enzymatic Ester Hydrolysis.

Chem Biodivers 2021 Jan 3;18(1):e2000829. Epub 2020 Dec 3.

School of Pharmaceutical Sciences, South-Central University of Nationalities, Wuhan, 430074, P. R. China.

A novel pH-activatable fluorescent probe, 1-(propan-2-yl)-9H-pyrido[3,4-b]indole-3-carboxylic acid (L-1), based on β-carboline derivatives, has been developed, which displays significant fluorescent response toward pH variation with high selectivity, good photo-stability and favorable pKa value. Moreover, L-1 can dynamically monitor the release of protons during ester hydrolysis reaction in consistent with enzymatic kinetics manner. Read More

View Article and Full-Text PDF
January 2021

Selective photo-ablation of glioma cells using an enzyme activatable photosensitizer.

Chem Commun (Camb) 2020 Nov 22;56(89):13860-13863. Epub 2020 Oct 22.

Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, New York, NY 10021, USA.

An activatable photosensitizer based on methylene blue was developed and validated for its efficacy in the selective killing of γ-glutamyl transpeptidase expressing cells. The O deactivation via bond breakage, rapid in situ enzymatic photosensitivity conversion, long lysosomal retention, and nucleus relocation collectively contribute to its strong and selective photodynamic effects. Read More

View Article and Full-Text PDF
November 2020

Visible light generation of high-valent metal-oxo intermediates and mechanistic insights into catalytic oxidations.

J Inorg Biochem 2020 11 8;212:111246. Epub 2020 Sep 8.

Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America.

High-valent metal-oxo complexes play central roles as active oxygen atom transfer (OAT) agents in many enzymatic and synthetic oxidation catalysis. This review focuses on our recent advances in application of photochemical approaches to probe the oxidizing metal-oxo species with different metals and macrocyclic ligands. Under visible light irradiation, a variety of important metal-oxo species including iron-oxo porphyrins, manganese-oxo porphyrin/corroles, ruthenium-oxo porphyrins, and chromium-oxo salens have been successfully generated. Read More

View Article and Full-Text PDF
November 2020

Proton-Conductive Melanin-Like Fibers through Enzymatic Oxidation of a Self-Assembling Peptide.

Adv Mater 2020 Nov 15;32(46):e2003511. Epub 2020 Oct 15.

Advanced Science Research Center (ASRC) at the Graduate Center, City University of New York (CUNY), 85 St Nicholas Terrace, New York, NY, 10031, USA.

Melanin pigments have various properties that are of technological interest including photo- and radiation protection, rich coloration, and electronic functions. Nevertheless, laboratory-based synthesis of melanin and melanin-like materials with morphologies and chemical structures that are specifically optimized for these applications, is currently not possible. Here, melanin-like materials that are produced by enzymatic oxidation of a supramolecular tripeptide structures that are rich in tyrosine and have a 1D morphology are demonstrated, that are retained during the oxidation process while conducting tracks form through oxidative tyrosine crosslinking. Read More

View Article and Full-Text PDF
November 2020

Light-driven assembly of biocompatible fluorescent chitosan hydrogels with self-healing ability.

J Mater Chem B 2020 11;8(42):9804-9811

'Materials + Technologies' Group, Department of Chemical and Environmental Engineering, Engineering College of Gipuzkoa, University of the Basque Country, Plaza Europa 1, 20018 Donostia-San Sebastián, Spain.

Nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) was successfully used to cross-link complementary tetrazole and maleimide chitosan derivatives into hydrogel networks using irradiation. The photo-click reaction resulted in the formation of robust fluorescent hydrogels with an emission signal at around 530 nm. The degree of cross-linking and the resulting hydrogel properties such as pH sensitivity and swelling were influenced by the tetrazole/maleimide ratio and the length of irradiation. Read More

View Article and Full-Text PDF
November 2020

Dissolved organic matter protects mosquito larvae from damaging solar UV radiation.

PLoS One 2020 7;15(10):e0240261. Epub 2020 Oct 7.

Department of Biology, Miami University, Oxford, Ohio, United States of America.

Mosquitoes have increased in their abundance and geographic distribution in northeastern North America, coinciding with an increase in extreme precipitation events and up to a doubling of dissolved organic matter (DOM) concentrations in some inland waters. Increases in DOM can reduce exposure of mosquito larvae to solar ultraviolet (UV) radiation. Although mosquito larvae are most common in shaded habitats, almost nothing is known about their susceptibility to damage by solar UV radiation, or the ability of DOM to create a refuge from damaging UV in their shallow-water habitats. Read More

View Article and Full-Text PDF
December 2020

Au nanoparticle-decorated ZnO nanorods as fluorescent non-enzymatic glucose probe.

Mikrochim Acta 2020 09 25;187(10):577. Epub 2020 Sep 25.

Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001, Leuven, Belgium.

ZnO nanorods (NRs) synthesized by a hydrothermal method and decorated with Au nanoparticles (NPs) were used for fluorescent non-enzymatic glucose detection. The detection is based on the photoluminescence (PL) quenching of ZnO NRs/Au NPs (at 382 nm under 325 nm excitation) exposed to glucose. The sensor exhibits a high sensitivity of (22 ± 2) % mM (defined as percentage change of the PL peak intensity per mM) and a limit of detection (LOD) as low as 0. Read More

View Article and Full-Text PDF
September 2020

Photo-biocatalytic Cascades: Combining Chemical and Enzymatic Transformations Fueled by Light.

Chembiochem 2021 Mar 6;22(5):790-806. Epub 2020 Nov 6.

Groningen Research Institute of Pharmacy, Department of Chemical and Pharmaceutical Biology, Antonius Deusinglaan 1, 9713 AV, Groningen (The, Netherlands.

In the field of green chemistry, light - an attractive natural agent - has received particular attention for driving biocatalytic reactions. Moreover, the implementation of light to drive (chemo)enzymatic cascade reactions opens up a golden window of opportunities. However, there are limitations to many current examples, mostly associated with incompatibility between the enzyme and the photocatalyst. Read More

View Article and Full-Text PDF

Photo-Protective Mechanisms and the Role of Poly (ADP-Ribose) Polymerase Activity in a Facultative CAM Plant Exposed to Long-Term Water Deprivation.

Plants (Basel) 2020 Sep 12;9(9). Epub 2020 Sep 12.

Department of Biology, University of Naples Federico II, Via Cinthia, 80126 Naples, Italy.

The Crassulacean acid metabolism (CAM) pathway helps plants to alleviate the oxidative stress under drought, but the shift to CAM-idling may expose plants to the overproduction of reactive oxygen species causing cell damages. The facultative CAM species L., was subjected to long-term water deprivation to assess the photo-protective strategies and the poly (ADP-ribose) polymerase (PARP) activity during water stress and plant capability to recover from the stress. Read More

View Article and Full-Text PDF
September 2020

Differential Regulation of Phytoene Synthase PSY1 During Fruit Carotenogenesis in Cultivated and Wild Tomato Species ( section Lycopersicon).

Plants (Basel) 2020 Sep 9;9(9). Epub 2020 Sep 9.

Institute of Bioengineering, Research Center of Biotechnology, Russian Academy of Sciences, 119071 Moscow, Russia.

In plants, carotenoids define fruit pigmentation and are involved in the processes of photo-oxidative stress defense and phytohormone production; a key enzyme responsible for carotene synthesis in fruit is phytoene synthase 1 (PSY1). Tomatoes ( section Lycopersicon) comprise cultivated () as well as wild species with different fruit color and are a good model to study carotenogenesis in fleshy fruit. In this study, we identified homologous genes in five section Lycopersicon species, including domesticated red-fruited and wild yellow-fruited and green-fruited , and . Read More

View Article and Full-Text PDF
September 2020

Increasing the chemical space of proteins in living cells via genetic code expansion.

Curr Opin Chem Biol 2020 10 7;58:112-120. Epub 2020 Sep 7.

Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, Group of Synthetic Biochemistry, Technical University of Munich, Institute for Advanced Study, Lichtenbergstr. 4, 85748, Garching, Germany. Electronic address:

In recent years it has become possible to genetically encode an expanded set of designer amino acids with tailored chemical and physical properties (dubbed unnatural amino acids, UAAs) into proteins in living cells by expanding the genetic code. Together with developments in chemistries that are amenable to and selective within physiological settings, these strategies have started to have a big impact on biological studies, as they enable exciting in cellulo applications. Here we highlight recent advances to covalently stabilize transient protein-protein interactions and capture enzyme substrate-complexes in living cells using proximity-triggered and residue-selective photo-induced crosslinking approaches. Read More

View Article and Full-Text PDF
October 2020

Enhanced DNA repair by DNA photolyase bearing an artificial light-harvesting chromophore.

Nucleic Acids Res 2020 10;48(18):10076-10086

Division of Chemistry, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.

Photolyases are flavoenzymes responsible for the repair of carcinogenic DNA damage caused by ultraviolet radiation. They harbor the catalytic cofactor flavin adenine dinucleotide (FAD). The light-driven electron transfer from the excited state of the fully-reduced form of FAD to the DNA lesions causes rearrangement of the covalent bonds, leading to the restoration of intact nucleobases. Read More

View Article and Full-Text PDF
October 2020

Stimuli-responsive azobenzene-quantum dots for multi-sensing of dithionite, hypochlorite, and azoreductase.

Mikrochim Acta 2020 08 2;187(8):481. Epub 2020 Aug 2.

Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.

A new fluorescence turn-on sensing platform has been developed applicable for sensitive profiling of multiple chemical and biological analytes, using azobenzene-quantum dot as a new stimuli-responsive optical nanoprobe. An azobenzene-carrying compound bis [4, 4'-(dithiophenyl azo)-1, 3-benzenediamine] (DTPABDA) is for the first time reported to be used for conjugation with CdSe/ZnS core/shell quantum dots (QDs) via the ligand exchange reaction. Due to the photo-induced electron-transfer (PET) effect, the electron-withdrawing azobenzene groups of DTPABDA can significantly cause the photoluminescence (PL) of QDs quenched. Read More

View Article and Full-Text PDF