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1.
Nat Commun ; 12(1): 5216, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471137

RESUMO

Bacterial biosensors, or bactosensors, are promising agents for medical and environmental diagnostics. However, the lack of scalable frameworks to systematically program ligand detection limits their applications. Here we show how novel, clinically relevant sensing modalities can be introduced into bactosensors in a modular fashion. To do so, we have leveraged a synthetic receptor platform, termed EMeRALD (Engineered Modularized Receptors Activated via Ligand-induced Dimerization) which supports the modular assembly of sensing modules onto a high-performance, generic signaling scaffold controlling gene expression in E. coli. We apply EMeRALD to detect bile salts, a biomarker of liver dysfunction, by repurposing sensing modules from enteropathogenic Vibrio species. We improve the sensitivity and lower the limit-of-detection of the sensing module by directed evolution. We then engineer a colorimetric bactosensor detecting pathological bile salt levels in serum from patients having undergone liver transplant, providing an output detectable by the naked-eye. The EMeRALD technology enables functional exploration of natural sensing modules and rapid engineering of synthetic receptors for diagnostics, environmental monitoring, and control of therapeutic microbes.


Assuntos
Bactérias/metabolismo , Biomarcadores/metabolismo , Técnicas Biossensoriais , Proteínas de Transporte/metabolismo , Patologia Molecular/métodos , Bactérias/genética , Ácidos e Sais Biliares/sangue , Técnicas Biossensoriais/métodos , Proteínas de Transporte/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Humanos , Transplante de Fígado , Engenharia Metabólica/métodos , Sensibilidade e Especificidade , Alinhamento de Sequência , Vibrio , Vibrioses/diagnóstico
2.
Nat Commun ; 12(1): 4845, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381036

RESUMO

The human gut microbiota is increasingly recognized as an important factor in modulating innate and adaptive immunity through release of ligands and metabolites that translocate into circulation. Urbanizing African populations harbor large intestinal diversity due to a range of lifestyles, providing the necessary variation to gauge immunomodulatory factors. Here, we uncover a gradient of intestinal microbial compositions from rural through urban Tanzanian, towards European samples, manifested both in relative abundance and genomic variation observed in stool metagenomics. The rural population shows increased Bacteroidetes, led by Prevotella copri, but also presence of fungi. Measured ex vivo cytokine responses were significantly associated with 34 immunomodulatory microbes, which have a larger impact on circulating metabolites than non-significant microbes. Pathway effects on cytokines, notably TNF-α and IFN-γ, differential metabolome analysis and enzyme copy number enrichment converge on histidine and arginine metabolism as potential immunomodulatory pathways mediated by Bifidobacterium longum and Akkermansia muciniphila.


Assuntos
Citocinas/imunologia , Microbioma Gastrointestinal/fisiologia , População Rural , População Urbana , Adulto , Arginina/metabolismo , Bactérias/imunologia , Bactérias/isolamento & purificação , Bactérias/metabolismo , Dieta , Feminino , Microbioma Gastrointestinal/imunologia , Histidina/metabolismo , Humanos , Imunomodulação , Masculino , Redes e Vias Metabólicas , Metaboloma/imunologia , Fatores Socioeconômicos , Tanzânia , Urbanização
3.
J Microbiol ; 59(9): 827-839, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34382149

RESUMO

Probiotics effectively prevent and improve metabolic diseases such as diabetes by regulating the intestinal microenvironment and gut microbiota. However, the effects of probiotics in gestational diabetes mellitus are not clear. Here, we showed that probiotic supplements significantly improved fasting blood glucose in a gestational diabetes mellitus rat model. To further understand the mechanisms of probiotics in gestational diabetes mellitus, the gut microbiota were analyzed via 16S rRNA sequencing. We found that compared with the normal pregnant group, the gestational diabetes mellitus rats had decreased diversity of gut microbiota. Moreover, probiotic supplementation restored the diversity of the gut microbiota in gestational diabetes mellitus rats, and the gut microbiota structure tended to be similar to that of normal pregnant rats. In particular, compared with gestational diabetes mellitus rats, the abundance of Firmicutes and Actinobacteria was higher after probiotic supplementation. Furthermore, activating carbohydrate metabolism and membrane transport pathways may be involved in the potential mechanisms by which probiotic supplements alleviate gestational diabetes mellitus. Overall, our results suggested that probiotic supplementation might be a novel approach to restore the gut microbiota of gestational diabetes mellitus rats and provided an experimental evidence for the use of probiotic supplements to treat gestational diabetes mellitus.


Assuntos
Diabetes Gestacional/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Probióticos/administração & dosagem , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/metabolismo , Metabolismo dos Carboidratos , Carboidratos , Diabetes Gestacional/metabolismo , Diabetes Gestacional/microbiologia , Suplementos Nutricionais/análise , Feminino , Masculino , Gravidez , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Ratos , Ratos Sprague-Dawley
4.
Nat Commun ; 12(1): 4743, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362911

RESUMO

Biology has evolved a variety of agents capable of permeabilizing and disrupting lipid membranes, from amyloid aggregates, to antimicrobial peptides, to venom compounds. While often associated with disease or toxicity, these agents are also central to many biosensing and therapeutic technologies. Here, we introduce a class of synthetic, DNA-based particles capable of disrupting lipid membranes. The particles have finely programmable size, and self-assemble from all-DNA and cholesterol-DNA nanostructures, the latter forming a membrane-adhesive core and the former a protective hydrophilic corona. We show that the corona can be selectively displaced with a molecular cue, exposing the 'sticky' core. Unprotected particles adhere to synthetic lipid vesicles, which in turn enhances membrane permeability and leads to vesicle collapse. Furthermore, particle-particle coalescence leads to the formation of gel-like DNA aggregates that envelop surviving vesicles. This response is reminiscent of pathogen immobilisation through immune cells secretion of DNA networks, as we demonstrate by trapping E. coli bacteria.


Assuntos
Bactérias/metabolismo , DNA/química , Lipídeos de Membrana/química , Permeabilidade da Membrana Celular , Escherichia coli/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Lipídeos de Membrana/metabolismo , Nanoestruturas/química , Tamanho da Partícula , Proteínas Citotóxicas Formadoras de Poros
5.
Nat Commun ; 12(1): 4748, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362927

RESUMO

Encapsulins are a class of microbial protein compartments defined by the viral HK97-fold of their capsid protein, self-assembly into icosahedral shells, and dedicated cargo loading mechanism for sequestering specific enzymes. Encapsulins are often misannotated and traditional sequence-based searches yield many false positive hits in the form of phage capsids. Here, we develop an integrated search strategy to carry out a large-scale computational analysis of prokaryotic genomes with the goal of discovering an exhaustive and curated set of all HK97-fold encapsulin-like systems. We find over 6,000 encapsulin-like systems in 31 bacterial and four archaeal phyla, including two novel encapsulin families. We formulate hypotheses about their potential biological functions and biomedical relevance, which range from natural product biosynthesis and stress resistance to carbon metabolism and anaerobic hydrogen production. An evolutionary analysis of encapsulins and related HK97-type virus families shows that they share a common ancestor, and we conclude that encapsulins likely evolved from HK97-type bacteriophages.


Assuntos
Bacteriófagos/metabolismo , Capsídeo/metabolismo , Células Procarióticas/metabolismo , Células Procarióticas/virologia , Archaea/metabolismo , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteriófagos/genética , Evolução Biológica , Vias Biossintéticas/genética , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Vírus de DNA/metabolismo , Filogenia , Virulência
6.
Biomed Res Int ; 2021: 6620574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34337038

RESUMO

In this study, 16S rRNA high-throughput sequencing technology was used to analyze the composition and diversity of bacterial and fungal communities in mushroom residue samples at different composting stages. During the composting process, the maximum temperature in the center of the pile can reach 52.4°C, and the temperature above 50°C has been maintained for about 8 days. The results showed that Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, and Chloroflexi were the main microorganisms in the composting process, accounting for 98.9%-99.7% of the total bacteria. Furthermore, in order to obtain the protein expressed in each stage of composting, the nonstandard quantitative method (label free) was used to analyze it quantitatively by mass spectrometry, anda total of 22815 proteins were identified. It indicated that the number of identified proteins related to cellulose decomposition and the number of differentially expressed proteins were significantly enriched, and the functional proteins related to cellulose decomposition had significant stage correspondence.


Assuntos
Agaricales/metabolismo , Microbiota , Aerobiose , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Celulose/metabolismo , Compostagem , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Peptídeos/metabolismo , Proteômica , Temperatura
7.
Molecules ; 26(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443585

RESUMO

Crocodiles are remarkable animals that have the ability to endure extremely harsh conditions and can survive up to a 100 years while being exposed to noxious agents that are detrimental to Homo sapiens. Besides their immunity, we postulate that the microbial gut flora of crocodiles may produce substances with protective effects. In this study, we isolated and characterized selected bacteria colonizing the gastrointestinal tract of Crocodylusporosus and demonstrated their inhibitory effects against three different cancerous cell lineages. Using liquid chromatography-mass spectrometry, several molecules were identified. For the first time, we report partial analyses of crocodile's gut bacterial molecules.


Assuntos
Jacarés e Crocodilos/microbiologia , Bactérias/isolamento & purificação , Microbioma Gastrointestinal , Animais , Bactérias/metabolismo , Linhagem Celular Tumoral
8.
Bioresour Technol ; 340: 125675, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34333349

RESUMO

This study investigated the impact of the potential cellulose degrading bacteria that could be bioaugmented in the solid-state anaerobic digestion (SSAD) of bagasse to enhance the methane yield. The prospective anaerobic cellulose degrading bacteria was isolated from the soil. SSAD experiments were organized with & without bioaugmentation with a substrate total solid (TS) of 25%, 30%, 40% and 50% at an optimized feed to microorganism (F/M) ratio of 1:1. The maximum yield of 0.44 L CH4/ (g VS added) was obtained from bioaugmented bagasse at a TS of 40% whereas it was 0.34 L CH4/(g VS added) for non-bioaugmented bagasse. The isolated bacterial strain was identified that belongs species Pseudomonas of Gamma Proteobacteria which exhibited good cellulolytic activity. Metagenomic studies found 90% of archaeal microorganisms affiliated to Methanosaeta, a strict acetoclastic methanogen.


Assuntos
Metano , Saccharum , Anaerobiose , Bactérias/metabolismo , Reatores Biológicos , Celulose/metabolismo , Estudos Prospectivos , Saccharum/metabolismo
9.
Nat Commun ; 12(1): 5032, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413314

RESUMO

Methane, along with other short-chain alkanes from some Archean metasedimentary rocks, has unique isotopic signatures that possibly reflect the generation of atmospheric greenhouse gas on early Earth. We find that alkane gases from the Kidd Creek mines in the Canadian Shield are microbial products in a Neoarchean ecosystem. The widely varied hydrogen and relatively uniform carbon isotopic compositions in the alkanes infer that the alkanes result from the biodegradation of sediment organic matter with serpentinization-derived hydrogen gas. This proposed process is supported by published geochemical data on the Kidd Creek gas, including the distribution of alkane abundances, stable isotope variations in alkanes, and CH2D2 signatures in methane. The recognition of Archean microbial methane in this work reveals a biochemical process of greenhouse gas generation before the Great Oxidation Event and improves the understanding of the carbon and hydrogen geochemical cycles.


Assuntos
Bactérias/metabolismo , Planeta Terra , Gases/química , Sedimentos Geológicos/química , Hidrogênio/química , Hidrogênio/metabolismo , Metano/metabolismo , Fenômenos Microbiológicos , Alcanos/química , Alcanos/metabolismo , Biodegradação Ambiental , Canadá , Isótopos de Carbono/química , Ecossistema , Metano/química , Oxirredução
10.
Molecules ; 26(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34443542

RESUMO

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of Escherichia coli and Pseudomonas aeruginosa. This study highlights a potential clinical application of the presented polymeric platform.


Assuntos
Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Nanopartículas/química , Polímeros/farmacologia , Células 3T3 , Animais , Biomassa , Sobrevivência Celular/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Polímeros/síntese química , Polímeros/química
11.
Nat Microbiol ; 6(9): 1118-1128, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34446927

RESUMO

Environmental bacteria, such as Streptomyces spp., produce specialized metabolites that are potent antibiotics and therapeutics. Selected specialized antimicrobials are co-produced and function together synergistically. Co-produced antimicrobials comprise multiple chemical classes and are produced by a wide variety of bacteria in different environmental niches, suggesting that their combined functions are ecologically important. Here, we highlight the exquisite mechanisms that underlie the simultaneous production and functional synergy of 16 sets of co-produced antimicrobials. To date, antibiotic and antifungal discovery has focused mainly on single molecules, but we propose that methods to target co-produced antimicrobials could widen the scope and applications of discovery programs.


Assuntos
Antibacterianos/biossíntese , Bactérias/química , Bactérias/metabolismo , Antibacterianos/farmacologia , Bactérias/classificação , Bactérias/genética , Microbiologia Ambiental
12.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360611

RESUMO

Due to the high exposition to changing environmental conditions, bacteria have developed many mechanisms enabling immediate adjustments of gene expression. In many cases, the required speed and plasticity of the response are provided by RNA-dependent regulatory mechanisms. This is possible due to the very high dynamics and flexibility of an RNA structure, which provide the necessary sensitivity and specificity for efficient sensing and transduction of environmental signals. In this review, we will discuss the current knowledge about known bacterial regulatory mechanisms which rely on RNA structure. To better understand the structure-driven modulation of gene expression, we describe the basic theory on RNA structure folding and dynamics. Next, we present examples of multiple mechanisms employed by RNA regulators in the control of bacterial transcription and translation.


Assuntos
Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Conformação de Ácido Nucleico , Dobramento de RNA , RNA Bacteriano/química , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Proteínas de Bactérias/genética , Transcrição Genética
13.
Nutrients ; 13(7)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34371938

RESUMO

A still growing interest between human nutrition in relation to health and disease states can be observed. Dietary components shape the composition of microbiota colonizing our gastrointestinal tract which play a vital role in maintaining human health. There is a strong evidence that diet, gut microbiota and their metabolites significantly influence our epigenome, particularly through the modulation of microRNAs. These group of small non-coding RNAs maintain cellular homeostasis, however any changes leading to impaired expression of miRNAs contribute to the development of different pathologies, including neoplastic diseases. Imbalance of intestinal microbiota due to diet is primary associated with the development of colorectal cancer as well as other types of cancers. In the present work we summarize current knowledge with particular emphasis on diet-microbiota-miRNAs axis and its relation to the development of colorectal cancer.


Assuntos
Bactérias/metabolismo , Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Dieta , Epigênese Genética , Microbioma Gastrointestinal , Intestinos/microbiologia , MicroRNAs/genética , Animais , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais/patologia , Dieta/efeitos adversos , Disbiose , Regulação Neoplásica da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , MicroRNAs/metabolismo , Medição de Risco , Fatores de Risco
14.
Nucleic Acids Res ; 49(13): 7525-7536, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34197592

RESUMO

Genome replication is a fundamental requirement for the proliferation of all cells. Throughout the domains of life, conserved DNA replication initiation proteins assemble at specific chromosomal loci termed replication origins and direct loading of replicative helicases (1). Despite decades of study on bacterial replication, the diversity of bacterial chromosome origin architecture has confounded the search for molecular mechanisms directing the initiation process. Recently a basal system for opening a bacterial chromosome origin (oriC) was proposed (2). In the model organism Bacillus subtilis, a pair of double-stranded DNA (dsDNA) binding sites (DnaA-boxes) guide the replication initiator DnaA onto adjacent single-stranded DNA (ssDNA) binding motifs (DnaA-trios) where the protein assembles into an oligomer that stretches DNA to promote origin unwinding. We report here that these core elements are predicted to be present in the majority of bacterial chromosome origins. Moreover, we find that the principle activities of the origin unwinding system are conserved in vitro and in vivo. The results suggest that this basal mechanism for oriC unwinding is broadly functionally conserved and therefore may represent an ancestral system to open bacterial chromosome origins.


Assuntos
Bactérias/genética , Cromossomos Bacterianos , Complexo de Reconhecimento de Origem , Origem de Replicação , Bacillus subtilis/genética , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética , Helicobacter pylori/genética , Viabilidade Microbiana , Motivos de Nucleotídeos
15.
Nat Chem Biol ; 17(8): 845-855, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34312558

RESUMO

One-carbon (C1) substrates are preferred feedstocks for the biomanufacturing industry and have recently gained attention owing to their natural abundance, low production cost and availability as industrial by-products. However, native pathways to utilize these substrates are absent in most biotechnologically relevant microorganisms. Recent advances in synthetic biology, genome engineering and laboratory evolution are enabling the first steps towards the creation of synthetic C1-utilizing microorganisms. Here, we briefly review the native metabolism of methane, methanol, CO2, CO and formate, and how these C1-utilizing pathways can be engineered into heterologous hosts. In addition, this review analyses the potential, the challenges and the perspectives of C1-based biomanufacturing.


Assuntos
Bactérias/metabolismo , Fungos/metabolismo , Engenharia Metabólica , Bactérias/citologia , Dióxido de Carbono/metabolismo , Monóxido de Carbono/metabolismo , Formiatos/metabolismo , Fungos/citologia , Metano/metabolismo , Metanol/metabolismo
16.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203411

RESUMO

Non-genetic phenotypic diversity plays a significant role in the chemotactic behavior of bacteria, influencing how populations sense and respond to chemical stimuli. First, we review the molecular mechanisms that generate phenotypic diversity in bacterial chemotaxis. Next, we discuss the functional consequences of phenotypic diversity for the chemosensing and chemotactic performance of single cells and populations. Finally, we discuss mechanisms that modulate the amount of phenotypic diversity in chemosensory parameters in response to changes in the environment.


Assuntos
Fatores Quimiotáticos/metabolismo , Quimiotaxia/fisiologia , Animais , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores Quimiotáticos/genética , Quimiotaxia/genética , Humanos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
17.
Biomolecules ; 11(7)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209734

RESUMO

Meroterpenoids are secondary metabolites formed due to mixed biosynthetic pathways which are produced in part from a terpenoid co-substrate. These mixed biosynthetically hybrid compounds are widely produced by bacteria, algae, plants, and animals. Notably amazing chemical diversity is generated among meroterpenoids via a combination of terpenoid scaffolds with polyketides, alkaloids, phenols, and amino acids. This review deals with the isolation, chemical diversity, and biological effects of 452 new meroterpenoids reported from natural sources from January 2016 to December 2020. Most of the meroterpenoids possess antimicrobial, cytotoxic, antioxidant, anti-inflammatory, antiviral, enzyme inhibitory, and immunosupressive effects.


Assuntos
Terpenos/química , Terpenos/isolamento & purificação , Terpenos/metabolismo , Alcaloides , Animais , Antibacterianos/metabolismo , Anti-Infecciosos/metabolismo , Antineoplásicos/metabolismo , Antioxidantes/metabolismo , Bactérias/metabolismo , Benzopiranos , Benzoquinonas , Produtos Biológicos/química , Vias Biossintéticas , Fungos/metabolismo , Humanos , Metabolismo Secundário/fisiologia , Sesquiterpenos
18.
Front Immunol ; 12: 624434, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34305883

RESUMO

Host immunity plays a central role in the regulation of anti-tumour responses during checkpoint inhibitor therapy (CIT). The mechanisms involved in long lasting remission remain unclear. Animal studies have revealed that the microbiome influences the host immune response. This is supported by human studies linking a higher microbial richness and diversity with enhanced responses to CIT. This review focuses on the role of diet, the microbiome and the microbiome-derived metabolome in enhancing responses to current CIT in solid tissue cancers. The Western diet has been associated with dysbiosis, inflammation and numerous metabolic disorders. There is preliminary evidence that lifestyle factors including a high fibre diet are associated with improved responses to CIT via a potential effect on the microbiota. The mechanisms through which the microbiota may regulate long-term immunotherapy responses have yet to be determined, although bacterial-metabolites including short chain fatty acids (SCFAs) are recognized to have an impact on T cell differentiation, and may affect T effector/regulatory T cell balance. SCFAs were also shown to enhance the memory potential of activated CD8 T cells. Many therapeutic approaches including dietary manipulation and fecal transplantation are currently being explored in order to enhance immunotherapy responses. The microbiome-derived metabolome may be one means through which bacterial metabolic products can be monitored from the start of treatment and could be used to identify patients at risk of poor immunotherapy responses. The current review will discuss recent advances and bring together literature from related fields in nutrition, oncology and immunology to discuss possible means of modulating immunity to improve responses to current CIT.


Assuntos
Dieta/métodos , Microbioma Gastrointestinal/efeitos dos fármacos , Inibidores de Checkpoint Imunológico/uso terapêutico , Metaboloma/imunologia , Neoplasias/tratamento farmacológico , Animais , Bactérias/metabolismo , Dieta/efeitos adversos , Disbiose/complicações , Microbioma Gastrointestinal/imunologia , Humanos , Imunomodulação , Estilo de Vida , Metaboloma/efeitos dos fármacos , Camundongos , Neoplasias/imunologia
19.
J Phys Chem Lett ; 12(27): 6292-6298, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34213343

RESUMO

Oscillatory features observed in two-dimensional electronic spectroscopy (2DES) manifest coherent vibrational and electronic dynamics and even the interplay of them. Recently, we developed a 2DES technique utilizing a pair of synchronized repetition-frequency-stabilized lasers, which enables the wide dynamic range measurements of 2DES signals rapidly. Here, we apply this dual-laser 2DES technique to investigate the electronic energy transfer (EET) process in bacterial light-harvesting complex II consisting of B800 and B850 circular aggregates at ambient temperature, and the coherent vibrational wavepakcet associated with the EET between the two aggregates are measured. Examining the principal component analysis of the time-resolved 2DES signal, we found that the EET from B800 to low-lying B850 states is modulated by a low-frequency (156 cm-1) vibrational mode of the exciton donor (B800). This observation suggests that the donor transition density is modulated by this vibration, which, in turn, modulates the energy transfer dynamics.


Assuntos
Bactérias/enzimologia , Complexos de Proteínas Captadores de Luz/metabolismo , Vibração , Bactérias/metabolismo , Bacterioclorofilas/metabolismo , Transferência de Energia , Fotossíntese
20.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207073

RESUMO

Laccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formation of water as a side-product and no requirement for cofactors. Importantly, addition of low-molecular-weight redox mediators that act as electron shuttles, promoting the oxidation of complex bulky substrates and/or of higher redox potential than the enzymes themselves, can further expand their substrate scope, in the so-called laccase-mediated systems (LMS). Laccase bioprocesses can be designed for efficiency at both acidic and basic conditions since it is known that fungal and bacterial laccases exhibit distinct optimal pH values for the similar phenolic and aromatic amines. This review covers studies on the synthesis of five- and six-membered ring heterocyclic cores, such as benzimidazoles, benzofurans, benzothiazoles, quinazoline and quinazolinone, phenazine, phenoxazine, phenoxazinone and phenothiazine derivatives. The enzymes used and the reaction protocols are briefly outlined, and the mechanistic pathways described.


Assuntos
Compostos Heterocíclicos/síntese química , Lacase/química , Lacase/metabolismo , Bactérias/metabolismo , Biocatálise/efeitos dos fármacos , Fungos/metabolismo , Oxirredução/efeitos dos fármacos
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