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1.
Arch Virol ; 166(10): 2881-2885, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34338875

RESUMO

Here, we describe a novel mycovirus, tentatively designated as "Botryosphaeria dothidea mitovirus 3" (BdMV3), isolated from Botryosphaeria dothidea strain FJ, which causes pear ring rot disease in Fujian Province, China. The complete genome nucleotide sequence of BdMV3 is 2538 nt in length and contains a single 2070-nt open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) of 689 amino acids (aa) using the fungal mitochondrial genetic code. BLASTp analysis revealed that the RdRp of BdMV3 shares 28.91%-69.36% sequence identity (query sequence coverage more than 90%) with those of members of the genus Mitovirus, with the highest sequence identity of 69.36% and 68.79% to the corresponding RdRp aa sequences of Rhizoctonia solani mitovirus 10 and Macrophomina phaseolina mitovirus 4, respectively. Phylogenetic analysis based on RdRp aa sequences indicated that BdMV3 is a new member of the genus Mitovirus in the family Mitoviridae.


Assuntos
Ascomicetos/virologia , Genoma Viral/genética , Doenças das Plantas/microbiologia , Pyrus/microbiologia , Vírus de RNA/genética , Sequência de Aminoácidos , China , Micovírus/classificação , Micovírus/genética , Fases de Leitura Aberta/genética , Filogenia , Vírus de RNA/classificação , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética
2.
Angew Chem Int Ed Engl ; 58(47): 16800-16805, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31486209

RESUMO

Surface recombination at the photoanode/electrolyte junction seriously impedes photoelectrochemical (PEC) performance. Through coating of photoanodes with oxygen evolution catalysts, the photocurrent can be enhanced; however, current systems for water splitting still suffer from high recombination. We describe herein a novel charge transfer system designed with BiVO4 as a prototype. In this system, porphyrins act as an interfacial-charge-transfer mediator, like a volleyball setter, to efficiently suppress surface recombination through higher hole-transfer kinetics rather than as a traditional photosensitizer. Furthermore, we found that the introduction of a "setter" can ensure a long lifetime of charge carriers at the photoanode/electrolyte interface. This simple interface charge-modulation system exhibits increased photocurrent density from 0.68 to 4.75 mA cm-2 and provides a promising design strategy for efficient photogenerated charge separation to improve PEC performance.

3.
Talanta ; 194: 493-500, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30609563

RESUMO

This paper developed a sensitive method for detecting hydroquinone by combining the unique optical properties of quantum dots and the specificity of enzymatic reactions. The interesting results shown that the fluorescence of graphite phase carbon nitride quantum dot (g-CNQDs) was quenched directly by benzoquinone or indirectly by hydroquinone (H2Q), and the possible quenching mechanism was proposed. Quinone might generate by catalyzing the oxidation of H2Q with horseradish peroxidase (HRP) in the presence of hydrogen peroxide. The intermediate quinone could effectively quench the fluorescence of g-CNQDs quantum dots. Therefore, a novel fluorescence probe based on g-CNQDs Quantum Dots was successfully used to detect H2Q by strongly quenching the fluorescence of g-CNQDs Quantum Dots which mediated by horseradish peroxidase enzymes. The detection limit was as low as 0.04 µM (S/N = 3), and the linear range was 0.5-11.6 µM. This kind of quantum dot-enzyme system has the advantages of simple operation, no modification of quantum dots, low cost, high sensitivity and short detection time.

4.
Anal Chem ; 91(3): 2319-2328, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30636409

RESUMO

We provide evidence of oxygen-involved electrochemiluminescence (ECL) of metal-free porphyrins and metalloporphyrins first. O2•- and OH•, which are oxygen intermediates, are indispensable for the formation of excited porphyrins, which has been proven by trapping free radical strategies. The wide differences regarding emission location and mechanism between metal-free porphyrins [including meso-tetra(4-methoxyphenyl)porphine (H2TMPP), meso-tetraphenylporphyrin (H2TPP), and meso-tetra(4-carboxyphenyl)porphine (H2TCPP)] and metalloporphyrins (MTPP) depend on whether protons are present in the center of the porphin ring. Besides, the oxygen-involved ECL of porphyrins can be controlled regularly by peripheral substituents with different polarities. Because of the stretched molecular structure and the decrease in electron density around the protons located at porphin ring, electron-withdrawing groups are more conducive to protons being attacked by O2•-, as well as the enhancement of porphyrins ECL. The ECL efficiency [ΦECL, which is normalized with respect to Ru(bpy)3(PF6)2 (taking ΦECL of Ru(bpy)3(PF6)2 = 1)] is gradually improved from H2TMPP (ΦECL = 0.16), to H2TPP (ΦECL = 2.20), to H2TCPP (ΦECL = 3.83); the ΦECL = 4.21 of Zn(II)TPP is significantly higher than those of other MTPPs [e.g., Co(II)TPP and Cu(II)TPP]. A deeper understanding regarding the improvement of porphyrins ECL efficiency and new application toward porphyrins-related devices can be achieved from this work.

5.
Food Res Int ; 108: 1-7, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29735037

RESUMO

In this work, a double shell material chitosan (CS)-recombinant soybean seed H-2 ferritin (H-2F) was fabricated to encapsulate epigallocatechin gallate (EGCG) molecules. EGCG-loaded H-2F complex (EHF) was firstly prepared by taking advantages of the reversible self-assembly of the ferritin, and the EHF-CS composite (EHFC) was fabricated by electrostatic interactions with binding number n of (4.1 ±â€¯0.11) and binding constant K of ((5.3 ±â€¯0.2) × 105 M-1), respectively. It was calculated that about 12.6 of EGCG molecules can be encapsulated in one H-2F ferritin cage with an encapsulation efficiency of 9.69% (w/w). SDS-PAGE analysis indicated that the CS binding to H-2F could inhibit ferritin degradation by pepsin and trypsin; the stability of EGCG molecules in EHFC was also significantly improved in simulated gastrointestinal tract. In addition, the chitosan-ferritin double shells were beneficial for the transport of EGCG across the Caco-2 monolayer model based on ferritin uptake. This work demonstrates a novel method to promote stabilization and absorption of food bioactive molecules.


Assuntos
Catequina/análogos & derivados , Quitosana/metabolismo , Digestão , Ferritinas/metabolismo , Absorção Intestinal , Nanopartículas , Células CACO-2 , Catequina/química , Catequina/metabolismo , Quitosana/análogos & derivados , Quitosana/química , Eletroforese em Gel de Poliacrilamida , Ferritinas/química , Suco Gástrico/metabolismo , Humanos , Secreções Intestinais/metabolismo , Microscopia Eletrônica de Transmissão , Nanotecnologia/métodos , Pepsina A/metabolismo , Espectrometria de Fluorescência , Eletricidade Estática , Tripsina/metabolismo
6.
Int J Biol Macromol ; 105(Pt 1): 252-261, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28693994

RESUMO

Ferritin is a shell-like carrier protein with an 8nm diameter cavity which endows a natural space to encapsulate food and drug components. In this work, phytoferritin was unprecedentedly glycosylated by chitosan to fabricate ferritin-chitosan Maillard reaction products (FCMPs) (grafting degree of 26.17%, 24h, 55°C). Results indicated that the amide I and II bands of ferritin were altered due to the chitosan grafting, whereas the ferritin spherical structure were retained. Simulated digestion analysis showed that the FCMPs were more resistant to pepsin and trypsin digestion as compared with ferritin alone. Furthermore, FCMPs were employed as carrier to encapsulate epigallocatechin gallate (EGCG) molecules with an encapsulation ratio of 12.87% (w/w), and the resulting FCMPs-EGCG complexes showed a slow release of EGCG in simulated gastrointestinal tract. Interestingly, different types of food components displayed different effects in EGCG release behavior from the FCMPs, wherein proanthocyanidin, milk and soy protein inhibited the EGCG release. In addition, the absorption of EGCG encapsulated in FCMPs in Caco-2 monolayer model was significantly improved as compared with free EGCG. This work provides a novel nano-vehicle for fabricating core-shell systems in food and drug delivery domain.


Assuntos
Absorção Fisico-Química , Catequina/análogos & derivados , Quitosana/química , Portadores de Fármacos/química , Ferritinas/química , Nanopartículas , Disponibilidade Biológica , Células CACO-2 , Catequina/química , Portadores de Fármacos/metabolismo , Portadores de Fármacos/farmacocinética , Estabilidade de Medicamentos , Ferritinas/metabolismo , Ferritinas/farmacocinética , Trato Gastrointestinal/metabolismo , Glicosilação , Humanos , Tamanho da Partícula
7.
J Food Sci ; 82(2): 350-357, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28071792

RESUMO

Rice bran albumin protein (RAP) is sensitive to thermal changes and tends to degrade when exposed to high-temperature processing. In this work, RAP-epigallocatechin-3-gallate (EGCG) complex (RAPE) was prepared and the thermal stability was evaluated. Fluorescence results showed that EGCG could interact with RAP with a binding number n of 0.0885:1 (EGCG:RAP, w/w) and a binding constant K of 1.02 (± 0.002) ×104 /M, suggesting both hydrogen bonding and van der Waals forces played an important role. FTIR analysis demonstrated that EGCG could induce secondary structural changes in RAP above a ratio of 1.6:1 (EGCG:RAP, w/w). Interestingly, the secondary structure changes of RAPE at different temperatures (25, 50, 60, 70, and 80 °C) were inhibited compared with that for RAP, suggesting RAPE was more resistant and stable to the heat treatment. In addition, a dense porous structure of RAPE was achieved due to the EGCG binding after thermal treatment. Furthermore, the Tpeak temperature of RAPE increased significantly from 64.58 to 74.16 °C and the enthalpy also increased from 85.53 to 138.52 J/g with a mass ratio increasing from 0 to 3.2 (EGCG:RAP, w/w), demonstrating the thermal stability of RAPE. In addition, the valine, methionine, and lysine content in RAPE were significantly higher than RAP following 80 °C treatment for 20 min (P < 0.05), exhibiting enhanced amino acid profiles, which might be due to EGCG-RAP interactions and microenvironment changes around relevant amino acids. These findings demonstrate that EGCG has the potential to improve the thermal stability of sensitive proteins and is beneficial for usage in the food industry.


Assuntos
Albuminas/química , Albuminas/metabolismo , Catequina/análogos & derivados , Oryza/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Catequina/química , Catequina/metabolismo , Temperatura Alta , Ligação de Hidrogênio , Oryza/química , Estrutura Secundária de Proteína , Termodinâmica
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