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1.
Adv Mater ; : e2403273, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38742630

RESUMO

Based on experimental and computational evidence, phthalocyanine (Pc) compounds in the form of quaternary bound metal-nitrogen (N) atoms are the most effective catalysts for oxygen reduction reaction (ORR). However, the heat treatment process used in their synthesis may compromise the ideal structure, causing the agglomeration of transition metals. To overcome this issue, we developed a novel method for synthesizing iron (Fe) single-atom catalysts with ideal structures supported by thermally exfoliated graphene oxide (GO). This was achieved through a short heat-treatment of only 2.5 min involving FePc and N,N-dimethylformamide in the presence of GO. According to the synthesis mechanism revealed by this study, carbon monoxide acts as a strong linker between the single Fe atoms and graphene. It facilitates the formation of a structure containing oxygen species between FeN4 and graphene, which provides high activity and stability for the ORR. These catalysts possess an enormous number of active sites and exhibit enhanced activity towards the alkaline ORR. They have demonstrated excellent performance when applied to real electrochemical devices, such as zinc-air batteries and anion exchange membrane fuel cells. We expect that the instantaneous heat treatment method developed in our study will aid in the development of high-performing single-atom catalysts. This article is protected by copyright. All rights reserved.

2.
Insects ; 15(4)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38667348

RESUMO

This study examined red palm weevil ecology in the United Arab Emirates to develop effective food baits, pheromone, and eco-friendly trapping methods. Three phases of investigation were conducted (from June to December 2023) on date palm farms in Ras Al Khaimah and Abu Dhabi. The first two phases, each 15 days long, were conducted in Ras Al Khaimah, whereas the third phase, 18 days long, was conducted in Abu Dhabi. Chemical attractants, such as existing pheromones and ethyl acetate, a newly synthesized ferruginol pheromone, and food baits, such as original dates, date paste, coconut water, and date palm syrup, were used to attract the weevils. Multi-funnel traps containing various attractant mixes were tested. The main activity of the red palm weevils was observed from 3:00 to 6:00 a.m., with 85.72 ± 3.39% being captured during this period, coinciding with cooler temperatures. When pheromones were added to the food bait, the capture rate increased by 6.95 ± 1.81 times. Combining food bait, ethyl acetate, and pheromones improved the capture rates by 3.14 ± 0.69 times compared to pheromones alone. The newly synthesized pheromone achieved capture rates 2.69 ± 0.07 times higher than those of the commercially available pheromone, confirming its suitability as a red palm weevil attractant.

3.
Cancers (Basel) ; 15(23)2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38067210

RESUMO

Lung adenocarcinoma is a crucial contributor to cancer-related mortality; however, effective treatments remain challenging. The present study aimed to investigate the role of hemoglobin subunit theta 1 (HBQ1), an α subunit of hemoglobin whose expression has recently been reported in non-erythroid cells, in lung adenocarcinoma. Comparative analysis showed that HBQ1 expression was significantly higher in lung adenocarcinoma tissues compared to normal lung tissues. Moreover, high HBQ1 expression was correlated with unfavorable overall survival and progression-free survival in patients, highlighting its potential as a prognostic marker. Our functional experiments revealed that when overexpressed, HBQ1 acts as an oncogene, enhancing cell proliferation, whereas HBQ1 knockdown inhibits it. Additionally, HBQ1 exhibited antioxidant properties by reducing basal reactive oxygen species levels, playing a crucial role in lung adenocarcinoma progression. These findings emphasize the critical role of HBQ1 in driving tumor growth and progression in lung adenocarcinoma. Our in vivo studies further supported the role of HBQ1 in lung adenocarcinoma. HBQ1 knockdown resulted in the inhibition of lung adenocarcinoma growth, demonstrating the potential of HBQ1 as a therapeutic target. Our findings highlight the importance of HBQ1 in lung adenocarcinoma and suggest its potential as both a diagnostic marker and a molecular target for therapeutic interventions.

4.
JACS Au ; 3(11): 3055-3065, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38034956

RESUMO

Intrinsically disordered proteins (IDPs) not only play important roles in biological processes but are also linked with the pathogenesis of various human diseases. Specific and reliable sensing of IDPs is crucial for exploring their roles but remains elusive due to structural plasticity. Here, we present the development of a new type of fluorescent protein for the ratiometric sensing and tracking of an IDP. A ß-strand of green fluorescent protein (GFP) was truncated, and the resulting GFP was further engineered to undergo the transition in the absorption maximum upon binding of a target motif within amyloid-ß (Aß) as a model IDP through rational design and directed evolution. Spectroscopic and structural analyses of the engineered truncated GFP demonstrated that a shift in the absorption maximum is driven by the change in the chromophore state from an anionic (460 nm) state into a neutral (390 nm) state as the Aß binds, allowing a ratiometric detection of Aß. The utility of the developed GFP was shown by the efficient and specific detection of an Aß and the tracking of its conformational change and localization in astrocytes.

5.
Antiviral Res ; 220: 105738, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37944822

RESUMO

Coronavirus Disease 2019 (COVID-19) pandemic is severely impacting the world, and tremendous efforts have been made to deal with it. Despite many advances in vaccines and therapeutics, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants remains an intractable challenge. We present a bivalent Receptor Binding Domain (RBD)-specific synthetic antibody, specific for the RBD of wild-type (lineage A), developed from a non-antibody protein scaffold composed of LRR (Leucine-rich repeat) modules through phage display. We further reinforced the unique feature of the synthetic antibody by constructing a tandem dimeric form. The resulting bivalent form showed a broader neutralizing activity against the variants. The in vivo neutralizing efficacy of the bivalent synthetic antibody was confirmed using a human ACE2-expressing mouse model that significantly alleviated viral titer and lung infection. The present approach can be used to develop a synthetic antibody showing a broader neutralizing activity against a multitude of SARS-CoV-2 variants.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Camundongos , Humanos , SARS-CoV-2/genética , Anticorpos , Técnicas de Visualização da Superfície Celular , Glicoproteína da Espícula de Coronavírus/genética , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico
6.
Comput Struct Biotechnol J ; 20: 5962-5965, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36345436

RESUMO

Fever is a typical symptom of most infectious diseases. While prolonged fever may be clinically undesirable, mild reversible fever (<39℃, 312 K) can potentiate the immune responses against pathogens. Here, using molecular dynamics and free energy calculations, we investigated the effect of febrile temperatures (38℃ to 40℃, 311 K to 313 K) on the immune complexes formed by the SARS-CoV-2 spike protein with two neutralizing monoclonal antibodies. In analyzing the conformational dynamics of the interactions between the antibodies and the spike protein under different thermal conditions, we found that, at mild fever temperatures (311-312 K), the binding affinities of the two antibodies improve when compared to the physiological body temperature (37℃, 310 K). Furthermore, only at 312 K, antibodies exert distinct mechanical effects on the receptor binding domains of the spike protein that may hinder SARS-CoV-2 infectivity. Enhanced antibody binding affinity may thus be obtained using appropriate temperature conditions.

7.
Front Plant Sci ; 13: 968466, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36061785

RESUMO

Isoflavones are major secondary metabolites that are exclusively produced by legumes, including soybean. Soy isoflavones play important roles in human health as well as in the plant defense system. The isoflavone content is influenced by minor-effect quantitative trait loci, which interact with polygenetic and environmental factors. It has been difficult to clarify the regulation of isoflavone biosynthesis because of its complex heritability and the influence of external factors. Here, using a genotype-by-sequencing-based genome-wide association mapping study, 189 mutant soybean genotypes (the mutant diversity pool, MDP) were genotyped on the basis of 25,646 high-quality single nucleotide polymorphisms (SNPs) with minor allele frequency of >0.01 except for missing data. All the accessions were phenotyped by determining the contents of 12 isoflavones in the soybean seeds in two consecutive years (2020 and 2021). Then, quantitative trait nucleotides (QTNs) related to isoflavone contents were identified and validated using multi-locus GWAS models. A total of 112 and 46 QTNs related to isoflavone contents were detected by multiple MLM-based models in 2020 and 2021, respectively. Of these, 12 and 5 QTNs were related to more than two types of isoflavones in 2020 and 2021, respectively. Forty-four QTNs were detected within the 441-Kb physical interval surrounding Gm05:38940662. Of them, four QTNs (Gm05:38936166, Gm05:38936167, Gm05:38940662, and Gm05:38940717) were located at Glyma.05g206900 and Glyma.05g207000, which encode glutathione S-transferase THETA 1 (GmGSTT1), as determined from previous quantitative trait loci annotations and the literature. We detected substantial differences in the transcript levels of GmGSTT1 and two other core genes (IFS1 and IFS2) in the isoflavone biosynthetic pathway between the original cultivar and its mutant. The results of this study provide new information about the factors affecting isoflavone contents in soybean seeds and will be useful for breeding soybean lines with high and stable concentrations of isoflavones.

8.
Int J Mol Sci ; 23(18)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36142354

RESUMO

In this study, we performed a genotyping-by-sequencing analysis and a genome-wide association study of a soybean mutant diversity pool previously constructed by gamma irradiation. A GWAS was conducted to detect significant associations between 37,249 SNPs, 11 agronomic traits, and 6 phytochemical traits. In the merged data set, 66 SNPs on 13 chromosomes were highly associated (FDR p < 0.05) with the following 4 agronomic traits: days of flowering (33 SNPs), flower color (16 SNPs), node number (6 SNPs), and seed coat color (11 SNPs). These results are consistent with the findings of earlier studies on other genetic features (e.g., natural accessions and recombinant inbred lines). Therefore, our observations suggest that the genomic changes in the mutants generated by gamma irradiation occurred at the same loci as the mutations in the natural soybean population. These findings are indicative of the existence of mutation hotspots, or the acceleration of genome evolution in response to high doses of radiation. Moreover, this study demonstrated that the integration of GBS and GWAS to investigate a mutant population derived from gamma irradiation is suitable for dissecting the molecular basis of complex traits in soybeans.


Assuntos
Estudo de Associação Genômica Ampla , Glycine max , Mapeamento Cromossômico , Genoma de Planta , Genótipo , Desequilíbrio de Ligação , Mutação , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Glycine max/genética
9.
Int J Pharm ; 625: 122059, 2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-35905933

RESUMO

Human interleukin-15 (hIL-15) has attracted a considerable attention as a promising cancer immunotherapeutic due to its function to directly stimulate the proliferation and cytotoxic activity of NK and T cells. Nevertheless, a relatively short half-life of hIL-15 requires repeated administration and higher doses, causing serious side effects. Here, we demonstrate an enhanced blood half-life and biological activity of hIL-15 through genetic fusion of a human serum albumin-specific protein binder (rHSA). The fusion construct (rHSA-IL15) was observed to maintain respective binding activities for both hIL-15 receptor α and human serum albumin. The rHSA-IL15 led to a significant increase in the secretion of Granzyme B and INF-γ by immune cells compare to free hIL-15, expanding the population of activated T cell subset such as CD4 + T and CD8+ T cells. The terminal half-life of the rHSA-IL15 was prolonged by around a 40-fold in transgenic mice expressing human serum albumin, compared to free hIL-15. The rHSA-IL15 resulted in distinct anti-tumor activities in xenograft SCC (squamous cell carcinoma) mouse and allograft melanoma mouse models through activation of NK and CD8+ T cells. The rHSA-IL15 is expected to be used in cancer immunotherapy, assisting in the development of other cytokines as immunotherapeutic agents with greater efficacy.


Assuntos
Interleucina-15 , Neoplasias , Animais , Linfócitos T CD8-Positivos , Proliferação de Células , Meia-Vida , Humanos , Interleucina-15/genética , Interleucina-15/metabolismo , Interleucina-2 , Camundongos , Neoplasias/tratamento farmacológico , Albumina Sérica , Albumina Sérica Humana/farmacologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-35805638

RESUMO

Biofouling is a significant problem in the aquaculture and marine shipping industries; thus, various antifouling methods have been developed to prevent the resultant economic losses. In the present study, the superhydrophobic surface of a lotus leaf was bio-mimicked to achieve antifouling. Specifically, fabric substrates with and without superhydrophobic coatings on the surface were installed on the Tongyeong yacht in December 2020 (group A) and April 2021 (group B), and the coverage of the attached invertebrates was recorded every month until August 2021. The coverage of solitary ascidians (Ascidiella aspersa and Ciona robusta) and branching bryozoans (Bugula neritina) was lower on the coated substrates than on the non-coated ones, and coating or non-coating was significantly correlated with the extent of coverage. Superhydrophobic substrates with a low surface energy and micro-nano dual structure may be unsuitable for the attachment of larvae. Therefore, superhydrophobic coating is a more effective and simpler method of antifouling for certain taxa than other antifouling strategies. However, the antifouling effect of the superhydrophobic substrate in group A reduced after 5 months from the first installation; thus, the durability of the antifouling coating should be further improved, and solving this problem remains a major task, necessitating further research.


Assuntos
Incrustação Biológica , Animais , Incrustação Biológica/prevenção & controle , Interações Hidrofóbicas e Hidrofílicas , Invertebrados , Larva
11.
Biology (Basel) ; 11(6)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35741351

RESUMO

Ecological rules such as Bergmann's rule and the temperature-size rule state that body-size decline is a universal response to warm temperatures in both homeotherms and poikilotherms. In the present study, we investigated the biological responses of Nannophya koreana, an endangered dragonfly species in Korea, by comparing body size in two habitats with large differences in water temperature, Mungyong-si (MG, terraced paddy fields) and Muui-do (MU, a mountainous wetland). To conserve the dragonfly populations, the collected larvae were photographed and released, and their head widths and body lengths were measured. There was no difference in the annual mean air temperature and precipitation between the two sites; however, the annual mean water temperature was substantially lower in MU than in MG. There was little difference in larval head width between the two sites; however, body length in the MU population was smaller than that in the MG population. Larval growth rate per 100-degree-days was 0.75 mm for MG and 1.16 for MU. The relationship between temperature and body size of N. koreana larvae showed opposite trends to Bergmann's rule and the temperature-size rule. Since the larval growth period during a year in MU was shorter than that in MG, the MU population potentially exhibits a higher growth rate as a mechanism of compensating for the low water temperature. Our study established the relationship between temperature and body size of N. koreana in two wetlands that had an obvious difference in water temperature despite being geographically close. The results highlight the importance of considering detailed factors such as habitat type when studying the temperature-size responses of organisms.

12.
Comput Struct Biotechnol J ; 20: 2169-2180, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35615020

RESUMO

The therapeutic efficacy of a protein binder largely depends on two factors: its binding site and its binding affinity. Advances in in vitro library display screening and next-generation sequencing have enabled accelerated development of strong binders, yet identifying their binding sites still remains a major challenge. The differentiation, or "binning", of binders into different groups that recognize distinct binding sites on their target is a promising approach that facilitates high-throughput screening of binders that may show different biological activity. Here we study the extent to which the information contained in the amino acid sequences comprising a set of target-specific binders can be leveraged to bin them, inferring functional equivalence of their binding regions, or paratopes, based directly on comparison of the sequences, their modeled structures, or their modeled interactions. Using a leucine-rich repeat binding scaffold known as a "repebody" as the source of diversity in recognition against interleukin-6 (IL-6), we show that the "Epibin" approach introduced here effectively utilized structural modelling and docking to extract specificity information encoded in the repebody amino acid sequences and thereby successfully recapitulate IL-6 binding competition observed in immunoassays. Furthermore, our computational binning provided a basis for designing in vitro mutagenesis experiments to pinpoint specificity-determining residues. Finally, we demonstrate that the Epibin approach can extend to antibodies, retrospectively comparing its predictions to results from antigen-specific antibody competition studies. The study thus demonstrates the utility of modeling structure and binding from the amino acid sequences of different binders against the same target, and paves the way for larger-scale binning and analysis of entire repertoires.

13.
Artigo em Inglês | MEDLINE | ID: mdl-35162107

RESUMO

A community of benthic invertebrates, including sessile adult-stage invertebrates, can negatively effect corrosion, deformation, and increased fuel consumption by attaching to artificial structures, a phenomenon known as marine biofouling. Investigating the relationship between benthic communities and artificial structures or substrates (to which the organisms attach) can help clarify the factors influencing marine biofouling. Therefore, in our study, natural (stone) and artificial (rubber, tarpaulin, and iron) substrates were installed in three harbors (Mokpo, Tongyeong, and Busan), and the structures of the communities attached to each substrate were compared. The total study period was 15 months (September 2016 to December 2017), and field surveys were performed at 3-month intervals. The three survey sites had significant differences in the structure of the sessile community present. In particular, Tongyeong was significantly different from Mokpo and Busan due to the continuous dominance of Cirripedia. When comparing natural and artificial substrate by sites, significant differences were observed in the community structure in all three surveyed sites. In Mokpo and Busan, colonial ascidians were dominant on natural substrate rather than artificial substrates; post-summer, Cirripedia coverage was higher on artificial substrates than natural substrate due to corrosion. Tongyeong showed a different pattern from that of Mokpo and Busan. After the summer, Bivalvia dominated on natural substrate over artificial substrates, affecting the differences between natural and artificial substrates. Our results demonstrate the recruitment patterns of sessile marine invertebrates according to substrate characteristics and can be used as basic information for biofouling management in marine environment.


Assuntos
Incrustação Biológica , Bivalves , Animais , Organismos Aquáticos , Ecossistema , Invertebrados
14.
Artigo em Inglês | MEDLINE | ID: mdl-35055831

RESUMO

We conducted an experiment to confirm the passability of chironomid larvae (Glyptotendipes tokunagai) in granular activated carbon (GAC) used in water treatment plants. After injecting larvae at different growth stages (first through fourth instars) into circular columns filled with GAC, the number of individuals and their locations within the GAC columns were recorded after 168 h. We found that more than 80% of the injected larvae in the first instar and 3.3% in the second instar passed, whereas none from the third and fourth instars had passed through the column. The second instar larvae were evenly distributed within the column, whereas the third and fourth instar larvae were mostly distributed within 10 cm of the upper layer of the GAC. Our results demonstrate the passability of chironomid larvae in GAC and can be used as basic information for water quality management in water treatment plants.


Assuntos
Chironomidae , Purificação da Água , Animais , Carvão Vegetal , Humanos , Larva , Purificação da Água/métodos
15.
Mol Biol Rep ; 48(9): 6387-6400, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34426904

RESUMO

BACKGROUND: Perilla frutescens (Lamiaceae) is distributed in East Asia and is classified into var. frutescens and crispa. P. frutescens is multipurpose crop for human health because of a variety of secondary metabolites such as phenolic compound and essential oil. However, a lack of genetic information has hindered the development and utilization of Perilla genotypes. METHODS AND RESULTS: This study was performed to develop expressed sequence tag-simple sequence repeat (EST-SSR) markers from P. frutescens var. crispa (wild type) and Antisperill (a mutant cultivar) and used them to assess the genetic diversity of, and relationships among, 94 P. frutescens genotypes. We obtained 65 Gb of sequence data comprising 632,970 transcripts by de novo RNA-sequencing. Of the 14,780 common SSRs, 102 polymorphic EST-SSRs were selected using in silico polymerase chain reaction (PCR). Overall, successful amplification from 58 EST-SSRs markers revealed remarkable genetic diversity and relationships among 94 P. frutescens genotypes. In total, 268 alleles were identified, with an average of 4.62 alleles per locus (range 2-11 alleles/locus). The average polymorphism information content (PIC) value was 0.50 (range 0.04-0.86). In phylogenetic and population structure analyses, the genotypes formed two major groups: Group I (var. crispa) and Group II (var. frutescens). CONCLUSION: This results suggest that 58 novel EST-SSR markers derived from wild-type cultivar (var. crispa) and its mutant cultivar (Antisperill) have potential uses for population genetics and recombinant inbred line mapping analyses, which will provide comprehensive insights into the genetic diversity and relationship of P. frutescens.


Assuntos
Etiquetas de Sequências Expressas , Repetições de Microssatélites/genética , Mutação , Perilla frutescens/genética , Polimorfismo Genético , Transcriptoma/genética , Alelos , Produtos Agrícolas/genética , Loci Gênicos , Genótipo , Filogenia , RNA-Seq/métodos
16.
Plants (Basel) ; 10(6)2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34063981

RESUMO

Soybean seeds are consumed worldwide owing to their nutritional value and health benefits. In this study we investigated the metabolic properties of 208 soybean mutant diversity pool (MDP) lines by measuring the isoflavone and fatty acid contents of the seed. The total isoflavone content (TIC) ranged from 0.88 mg/g to 7.12 mg/g and averaged 3.08 mg/g. The proportion of oleic acid among total fatty acids (TFA) ranged from 0.38% to 24.66% and averaged 11.02%. Based on the TIC and TFA among the 208 MDP lines, we selected six lines with altered isoflavone content and six lines with altered oleic acid content compared with those of the corresponding wild-types for measuring gene expression. Each of twelve genes from the isoflavone and fatty acid biosynthesis pathways were analyzed at three different seed developmental stages. Isoflavone biosynthetic genes, including CHI1A, IFS1, and IFS2, showed differences in stages and expression patterns among individuals and wild-types, whereas MaT7 showed consistently higher expression levels in three mutants with increased isoflavone content at stage 1. Expression patterns of the 12 fatty acid biosynthetic genes were classifiable into two groups that reflected the developmental stages of the seeds. The results will be useful for functional analysis of the regulatory genes involved in the isoflavone and fatty acid biosynthetic pathways in soybean.

17.
ACS Appl Mater Interfaces ; 13(20): 23915-23927, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33998226

RESUMO

Ruthenium (Ru) thin films deposited via atomic layer deposition (ALD) with a normal sequence and discrete feeding method (DFM) and their performance as a bottom electrode of dynamic random-access memory (DRAM) capacitors were compared. The DFM-ALD was performed by dividing the Ru feeding and purge steps of the conventional ALD process into four steps (shorter feeding time + purge time). The surface morphology of the Ru films was improved significantly with the DFM-ALD, and the preferred orientation of the Ru films was changed from relatively random to a <101>-oriented direction. Under the DFM-ALD condition, the higher susceptibility of oxygen atoms to the Ru electrode resulted in a higher proportion of the RuO2 formation on the Ru film surface during the subsequent TiO2 ALD process. This higher RuO2 portion leads to higher crystallinity of the local-epitaxially grown TiO2 films with a rutile phase. Such improvement also decreased the interfacial component of equivalent oxide thickness (EOTi) by ∼0.1 nm compared with the cases on sputtered Ru film, which showed an even smoother surface morphology. Consequently, the minimum EOT values when the Ru bottom electrodes deposited via DFM-ALD were adopted were 0.76 and 0.48 nm for TiO2 and Al-doped TiO2 films, respectively, while still satisfying the DRAM leakage current density specification (<10-7 A/cm2 at a capacitor voltage of 0.8 V).

18.
ACS Appl Mater Interfaces ; 13(21): 24624-24633, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34003000

RESUMO

A simple wet-chemical route for the preparation of core-shell-structured catalysts was developed to achieve high oxygen reduction reaction (ORR) activity with a low Pt loading amount. Nickel nitride (Ni3N) nanoparticles were used as earth-abundant metal-based cores to support thin Pt layers. To realize the site-selective formation of Pt layers on the Ni3N core, hydrogen molecules (H2) were used as a mild reducing agent. As H2 oxidation is catalyzed by the surface of Ni3N, the redox reaction between H2 and Pt(IV) in solution was facilitated on the Ni3N surface, which resulted in the selective deposition of Pt on Ni3N. The controlled Pt formation led to a subnanometer (0.5-1 nm)-thick Pt shell on the Ni3N core. By adopting the core-shell structure, higher ORR activity than the commercial Pt/C was achieved. Electrochemical measurements showed that the thin Pt layer on Ni3N nanoparticle exhibits 5 times higher mass activity and specific activity than that of commercial Pt/C. Furthermore, it is expected that the proposed simple wet-chemical method can be utilized to prepare various transition-metal-based core-shell nanocatalysts for a wide range of energy conversion reactions.

19.
J Chem Inf Model ; 61(4): 2099-2107, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33829791

RESUMO

Protein binders including antibodies are known not to bind to random sites of target proteins, and their functional effectiveness mainly depends on the binding region, called the epitope. For the development of protein binders with desired functions, it is thus critical to understand which surface region protein binders prefer (or do not prefer) to bind. The current methods for epitope prediction focus on static indicators such as structural geometry or amino acid propensity, whereas protein binding events are in fact a consequence of dynamic interactions. Here, we demonstrate that the preference for a binding site by protein binders is strongly related to the structural flexibility of a target protein surface. Molecular dynamics simulations on unbound forms of antigen structures revealed that the antigen surface in direct contact with antibodies is less flexible than the rest of the surface. This tendency was shown to be similar in other non-antibody protein binders such as affibody, DARPin, monobody, and repebody. We also found that the relatedness of epitopes to the structural flexibility of a target protein surface is dependent on the secondary structure elements of paratopes. Monobody and repebody, whose binding sites are composed of ß-strands, distinctively prefer to bind to a relatively more rigid region of a target protein. These observations enabled us to develop a simple epitope prediction method which shows a comparable performance to the commonly used ones.


Assuntos
Proteínas , Sítios de Ligação , Sítios de Ligação de Anticorpos , Epitopos , Ligação Proteica
20.
Plants (Basel) ; 10(2)2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33671964

RESUMO

Transposable elements (TEs)-major components of eukaryotic genomes-have the ability to change location within a genome. Because of their mobility, TEs are important for genome diversification and evolution. Here, a simple rapid method, using the consensus terminal inverted repeat sequences of PONG, miniature inverted-repeat transposable element (MITE)-Tourist (M-t) and MITE-Stowaway (M-s) as target region amplification polymorphism (TE-TRAP) markers, was employed to investigate the mobility of TEs in a gamma-irradiated soybean mutant pool. Among the different TE-TRAP primer combinations, the average polymorphism level and polymorphism information content value were 57.98% and 0.14, respectively. Only the PONG sequence separated the mutant population into three major groups. The inter-mutant population variance, determined using the PONG marker (3.151 and 29%) was greater than that of the M-t (2.209 and 20%) and M-s (2.766 and 18%) markers, whereas the reverse was true for the intra-mutant population variations, with M-t and M-s values, being 15.151 (82%) and 8.895 (80%), respectively, compared with the PONG marker (7.646 and 71%). Thus, the MITE markers revealed more dynamic and active mobility levels than the PONG marker in gamma-ray irradiated soybean mutant lines. The TE-TRAP technique associated with sensitive MITEs is useful for investigating genetic diversity and TE mobilization, providing tools for mutant selection in soybean mutation breeding.

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