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1.
Neuropsychobiology ; 82(2): 81-90, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36657428

RESUMO

INTRODUCTION: It is critical to develop accurate and universally available biomarkers for dementia diseases to appropriately deal with the dementia problems under world-wide rapid increasing of patients with dementia. In this sense, electroencephalography (EEG) has been utilized as a promising examination to screen and assist in diagnosing dementia, with advantages of sensitiveness to neural functions, inexpensiveness, and high availability. Moreover, the algorithm-based deep learning can expand EEG applicability, yielding accurate and automatic classification easily applied even in general hospitals without any research specialist. METHODS: We utilized a novel deep neural network, with which high accuracy of discrimination was archived in neurological disorders in the previous study. Based on this network, we analyzed EEG data of healthy volunteers (HVs, N = 55), patients with Alzheimer's disease (AD, N = 101), dementia with Lewy bodies (DLB, N = 75), and idiopathic normal pressure hydrocephalus (iNPH, N = 60) to evaluate the discriminative accuracy of these diseases. RESULTS: High discriminative accuracies were archived between HV and patients with dementia, yielding 81.7% (vs. AD), 93.9% (vs. DLB), 93.1% (vs. iNPH), and 87.7% (vs. AD, DLB, and iNPH). CONCLUSION: This study revealed that the EEG data of patients with dementia were successfully discriminated from HVs based on a novel deep learning algorithm, which could be useful for automatic screening and assisting diagnosis of dementia diseases.


Assuntos
Doença de Alzheimer , Aprendizado Profundo , Doença por Corpos de Lewy , Humanos , Doença por Corpos de Lewy/complicações , Doença por Corpos de Lewy/diagnóstico , Doença de Alzheimer/diagnóstico , Eletroencefalografia
2.
Xenobiotica ; 53(10-11): 613-620, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37966716

RESUMO

Dose adjustment based on renal function is essential in S-1, which contains the 5­fluorouracil prodrug tegafur, and platinum-based agent oxaliplatin (SOX) combination chemotherapy for colorectal cancer in patients with chronic kidney disease. However, limited evidence on dose adjustment in acute kidney injury (AKI) and challenges in determining dosing strategies. This study investigated the pharmacokinetics of SOX chemotherapy and renal biomarkers in rats.AKI was prepared by renal ischaemia-reperfusion injury in 1,2-dimethylhydrazine-induced colorectal cancer model rats. Serum creatinine (sCr) levels were determined as a renal biomarker. After administration of S-1 (2 mg/kg tegafur) and oxaliplatin (5 mg/kg), drug concentrations of tegafur, 5-FU, and platinum were measured in the plasma and tumours.No alterations in the area under the plasma concentration-time curve (AUC0-24h) values of 5-fluorouracil were observed between control and AKI model rats. The tumour concentrations of 5-fluorouracil in the mild and severe AKI groups were significantly lower than control group. The AUC0-24h for platinum increased with AKI severity. Notably, population pharmacokinetic analysis identified sCr as a covariate in platinum distribution after SOX chemotherapy.To optimise dose adjustment of SOX chemotherapy in patients with AKI, sCr may be a key factor in determining the appropriate dose.


Assuntos
Injúria Renal Aguda , Neoplasias Colorretais , Humanos , Ratos , Animais , Oxaliplatina , Tegafur/toxicidade , Tegafur/farmacocinética , Fluoruracila/uso terapêutico , Fluoruracila/farmacocinética , Rim/patologia , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Biomarcadores , Neoplasias Colorretais/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
3.
Biosci Biotechnol Biochem ; 87(8): 857-864, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37253619

RESUMO

Hydrophobins are small amphiphilic proteins that are conserved in filamentous fungi. They localized on the conidial surface to make it hydrophobic, which contributes to conidial dispersal in the air, and helps fungi to infect plants and mammals and degrade polymers. Hydrophobins self-assemble and undergo structural transition from the amorphous state to the rodlet (rod-like multimeric structure) state. However, it remains unclear whether the amorphous or rodlet state is biologically functional and what external factors regulate state transition. In this study, we analyzed the self-assembly of hydrophobin RolA of Aspergillus oryzae in detail and identified factors regulating this process. Using atomic force microscopy, we observed RolA rodlet formation over time, and determined "rodlet elongation rate" and "rodlet formation frequency." Changes in these kinetic parameters in response to pH and salt concentration suggest that RolA rodlet formation is regulated by the strength of ionic interactions between RolA molecules.


Assuntos
Aspergillus oryzae , Proteínas Fúngicas , Proteínas Fúngicas/metabolismo , Aspergillus oryzae/metabolismo , Polímeros/química , Polímeros/metabolismo , Interações Hidrofóbicas e Hidrofílicas
4.
Psychol Res ; 87(7): 2249-2258, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36821009

RESUMO

The ability to anticipate the sensory consequences of our actions (i.e., action-effects) is known to be important for intentional action initiation and control. Learned action-effects can select the responses that previously have been associated with them. What has been largely unexplored is how learned action-effect associations can aid action selection for effects that have not previously associated with an action but are similar to learned effects. In two studies, we aimed to show that when presented new, unknown action-effects, participants select the responses that have previously been associated with similar action-effects. In the first study (n = 27), action-effect similarity was operationalized via stimuli belonging to the same or different categories as the previously learned action-effects. In the second study (n = 31), action-effect similarity was realized via stimuli that require comparable motor responses in real life. Participants first learned that specific responses are followed by specific visual effect stimuli. In the test phase, learned effect stimuli, new but similar effect stimuli and new but dissimilar effect stimuli were presented ahead of the response. The findings revealed that both learned effect stimuli and new similar effect stimuli affected response times, whereas new dissimilar effects did not. When a learned or a new similar effect was followed by a learned response, compared to an unlearned response, the responses were faster. We interpret these findings in terms of action-effect learning. The action-effect once bound to an action is used to select an action if a similar effect for which no action has been learned yet is presented. However, it is noteworthy that, due to our design, other explanations for the found transfer are conceivable. We address these limitations in the General Discussion.


Assuntos
Cognição , Aprendizagem , Humanos , Aprendizagem/fisiologia , Tempo de Reação , Conhecimento
5.
Appl Environ Microbiol ; 88(6): e0208721, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35108098

RESUMO

Hydrophobins are small secreted amphipathic proteins ubiquitous among filamentous fungi. Hydrophobin RolA produced by Aspergillus oryzae attaches to solid surfaces, recruits polyesterase CutL1, and thus promotes hydrolysis of polyesters. Because the N-terminal region of RolA is involved in the interaction with CutL1, the orientation of RolA on the solid surface is important. However, the kinetic properties of RolA adsorption to solid surfaces with various chemical properties remain unclear, and RolA structures assembled after the attachment to surfaces are unknown. Using a quartz crystal microbalance (QCM), we analyzed the kinetic properties of RolA adsorption to the surfaces of QCM electrodes that had been chemically modified to become hydrophobic or charged. We also observed the assembled RolA structures on the surfaces by atomic force microscopy and performed molecular dynamics (MD) simulations of RolA adsorption to self-assembled monolayer (SAM)-modified surfaces. The RolA-surface interaction was considerably affected by the zeta potential of RolA, which was affected by pH. The interactions of RolA with the surface seemed to be involved in the self-assembly of RolA. Three types of self-assembled structures of RolA were observed: spherical, rod-like, and mesh-like. The kinetics of RolA adsorption and the structures formed depended on the amount of RolA adsorbed, chemical properties of the electrode surface, and the pH of the buffer. Adsorption of RolA to solid surfaces seemed to depend mainly on its hydrophobic interaction with the surfaces; this was supported by MD simulations, which suggested that hydrophobic Cys-Cys loops of RolA attached to all SAM-modified surfaces at all pH values. IMPORTANCE The adsorption kinetics of hydrophobins to solid surfaces and self-assembled structures formed by hydrophobin molecules have been studied mostly independently. In this report, we combined the kinetic analysis of hydrophobin RolA adsorption onto solid surfaces and observation of RolA self-assembly on these surfaces. Since RolA, whose isoelectric point is close to pH 4.0, showed higher affinity to the solid surfaces at pH 4.0 than at pH 7.0 or 10.0, the affinity of RolA to these surfaces depends mainly on hydrophobic interactions. Our combined analyses suggest that not only the adsorbed amount of RolA but also the chemical properties of the solid surfaces and the zeta potential of RolA affect the self-assembled RolA structures formed on these surfaces.


Assuntos
Aspergillus oryzae , Adsorção , Aspergillus oryzae/metabolismo , Proteínas Fúngicas/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Cinética , Propriedades de Superfície
6.
Biosci Biotechnol Biochem ; 86(8): 1031-1040, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35612987

RESUMO

The basidiomycetous yeast Pseudozyma antarctica, which has multiple auxotrophic markers, was constructed, without inserting a foreign gene, as the host strain for the introduction of multiple useful genes. P. antarctica was more resistant to ultraviolet (UV) irradiation than the model yeast Saccharomyces cerevisiae, and a Paura3 mutant (C867T) was obtained after 3 min of UV exposure. A uracil-auxotrophic marker (URA3) recycling system developed in ascomycetous yeasts and fungi was applied to the P. antarctica Paura3 strain. The PaLYS12 and PaADE2 loci were disrupted via site-directed homologous recombination of PaURA3 (pop-in), followed by the removal of PaURA3 (pop-out). In the obtained double auxotrophic strain (Palys12Δ, Paura3), PaADE2 was further disrupted, and PaURA3 was removed to obtain the triple auxotrophic strain PGB800 (Paura3, Palys12Δ, Paade2Δ). The whole-genome sequence of the PGB800 strain did not contain foreign genes used for genetic manipulation and disrupted PaADE2 and PaLYS12, and removed PaURA3, as planned.


Assuntos
Basidiomycota , Ustilaginales , Saccharomyces cerevisiae/genética , Uracila , Ustilaginales/genética
7.
Exp Brain Res ; 239(1): 67-78, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33098652

RESUMO

The theory of event coding, an influential framework for action planning, suggests that humans first integrate stimulus, response, and action effect into representation (an event file) via their contingencies, and then, the activation of expected action effects drives the associated response. While previous studies have typically examined such functions of action effects after, rather than before or during, the acquirement of the representation, Eitam et al. (Exp Brain Res 229:475-484, 2013a) demonstrated that the presence of immediate feedback to action (i.e., action effects) can instantly elicit faster responses than delayed feedback. However, the underlying mechanism of this faciliatory effect remains unclear. Specifically, while the response-effect relationship has been highlighted, the role of stimuli has not been investigated. To address this issue, the present study conducted four experiments. We first reproduced the faciliatory effects of immediate action effects with between- and within-participants design (Experiments 1 and 2, respectively). Then, we assessed whether immediate action effects facilitate response speed, when stimuli (Experiment 3) and a combination of stimuli and responses (Experiment 4) determined the delay of action effects. The identical response was executed faster when driven by stimuli associated with immediate effects than by those associated with lagged effects. This result indicates that immediate action effects do not reinforce the execution of specific motor actions itself, but facilitate actions depending on the stimulus-response relationship. We discuss the potential mechanism of the facilitation effect.


Assuntos
Desempenho Psicomotor , Humanos , Tempo de Reação
8.
Biosci Biotechnol Biochem ; 84(4): 678-685, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31876261

RESUMO

Hydrophobins are small, amphipathic proteins secreted by filamentous fungi. Hydrophobin RolA, which is produced by Aspergillus oryzae, attaches to solid surfaces, recruits the polyesterase CutL1, and consequently promotes hydrolysis of polyesters. Because this interaction requires the N-terminal, positively charged residue of RolA to be exposed on the solid surface, the orientation of RolA on the solid surface is important for recruitment. However, the process by which RolA forms the self-assembled structure at the interface remains unclear. Using the Langmuir-Blodgett technique, we analyzed the process by which RolA forms a self-assembled structure at the air-water interface and observed the structures on the hydrophobic or hydrophilic SiO2 substrates via atomic force microscopy. We found that RolA formed self-assembled films in two steps during phase transitions. We observed different assembled structures of RolA on hydrophilic and hydrophobic SiO2 substrates.


Assuntos
Aspergillus oryzae/metabolismo , Proteínas Fúngicas/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Dióxido de Silício/metabolismo , Propriedades de Superfície , Água/química
9.
Chem Pharm Bull (Tokyo) ; 68(8): 806-809, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32461519

RESUMO

The direct electron transfer between human cytoglobin (Cygb) and the electrode surface, which would allow manipulating the oxidation states of the heme iron in Cygb, was first observed by immobilizing Cygb on a nanoporous gold (NPG) electrode via a carboxy-terminated alkanethiol. The voltammetric performances of the wild type and mutated Cygb-immobilized NPG electrodes were evaluated in the absence or presence of potential substrates. The obtained results demonstrated that the usefulness of the proposed method in understanding the function of Cygb in molecular basis.


Assuntos
Citoglobina/química , Técnicas Eletroquímicas/métodos , Citoglobina/genética , Citoglobina/metabolismo , Eletrodos , Transporte de Elétrons , Ouro/química , Humanos , Peróxido de Hidrogênio/química , Cinética , Mutagênese Sítio-Dirigida , Nanoporos , Oxirredução , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação
10.
Fungal Genet Biol ; 130: 82-90, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31026589

RESUMO

The basidiomycetous yeast, Pseudozyma antarctica, has the ability to express industrially beneficial biodegradable plastic-degrading enzyme (PaE) and glycolipids. In this study, we developed a highly efficient gene-targeting method in P. antarctica using a CRISPR/Cas9 gene-editing approach. Transformation of protoplast cells was achieved by incubation with a ribonucleoprotein (RNP) complex prepared by mixing the Cas9 protein with a single-guide RNA together with donor DNA (dDNA) containing a selectable marker in vitro. The PaE gene was selected as the targeted locus for gene disruption and gene-disrupted colonies were readily detected by their ability to degrade polybutylene succinate-co-adipate on solid media. The accuracy of the gene conversion event was confirmed by colony PCR. An increase in the RNP mix increased both transformation and gene disruption efficiencies. Examining the effect of the homology arm length of the dDNA revealed that dDNA with homology arms longer than 0.1 kb induced efficient homologous recombination in our system. Furthermore, this system was successful in another targeted locus, PaADE2. Following the creation of RNP-induced double-strand break of the chromosomal DNA, dDNA could be inserted into the target locus even in the absence of homology arms.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes/métodos , Marcação de Genes/métodos , Ustilaginales/genética , Sequência de Bases , Proteína 9 Associada à CRISPR/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , DNA Fúngico/genética , Proteínas Fúngicas/genética , Genes Fúngicos/genética , Loci Gênicos , Recombinação Homóloga , Ribonucleoproteínas/genética , Transformação Genética
11.
Biosci Biotechnol Biochem ; 83(8): 1547-1556, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30714483

RESUMO

The basidiomycetous yeast Pseudozyma antarctica GB-4(0) esterase (PaE) is a promising candidate for accelerating degradation of used biodegradable plastics (BPs). To increase safety and reduce costs associated with the use of PaE, we constructed a self-cloning strain with high-PaE productivity. A Lys12 gene (PaLYS12)-deleted lysine auxotroph strain GB4-(0)-L1 was obtained from GB-4(0) by ultraviolet mutagenesis and nystatin enrichment. Subsequently, the PaE gene (PaCLE1) expression cassette consisting of GB-4(0)-derived PaCLE1, under the control of a xylose-inducible xylanase promoter with PaLYS12, was randomly introduced into the GB4-(0)-L1 genome. A PaE high-producing strain, PGB474, was selected from among the transformants by high throughput double-screening based on its ability to degrade emulsified polybutylene succinate-co-adipate. Quantitative PCR revealed that four copies of the PaE gene expression cassette were introduced into the PGB474 genome. PGB474 produced 2.0 g/L of PaE by xylose-fed-batch cultivation using a 3-L jar fermentor for 72 h.


Assuntos
Biodegradação Ambiental , DNA Fúngico/genética , Enzimas/metabolismo , Plásticos/metabolismo , Ustilaginales/genética , Lisina/genética , Mutação , Reação em Cadeia da Polimerase/métodos , Ustilaginales/enzimologia
12.
J Cosmet Sci ; 70(1): 17-31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30856093

RESUMO

Recent increases in air pollution have raised concerns about its adverse effects on human health. Sacran is a natural polysaccharide isolated from a cyanobacterium. We previously reported that sacran improves skin conditions because of its effects as an artificial barrier against external stimuli, which suggested that sacran might protect the skin against air pollutants. The goal of this study was to characterize the potential of sacran to protect human skin against damage from air pollutants and to compare sacran with hyaluronic acid (HA). Sacran that was topically applied on the skin stayed on the surface or in the stratum corneum. Sacran-treated filters had a shielding effect against benzo[a]pyrene (BaP) and aldehyde compounds contained in tobacco smoke. Sacran suppressed the upregulation of cytochrome P4501A1 messenger ribonucleic acid (mRNA), which is a xenobiotic-metabolizing enzyme induced by BaP, and other responses against tobacco smoke in HaCaT keratinocytes. Furthermore, topical application of a serum containing 0.04% sacran on the skin reduced levels of carbonylated proteins in corneocytes of tobacco smokers. Sacran showed superior effects in every characteristic measured, compared with HA. We conclude that sacran ameliorates the oxidative stress initiated by tobacco smoke by shielding the skin surface and protects human skin.


Assuntos
Nicotiana , Pele , Humanos , Polissacarídeos , Fumaça
13.
Biol Pharm Bull ; 41(10): 1554-1560, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30270324

RESUMO

Sacran, a polysaccharide isolated from the alga Aphanothece sacrum (Suizenji-nori), has unique physical and physiological characteristics. In a previous study, we reported that sacran improves skin conditions in individuals who suffer from atopic dermatitis (AD), focusing on its trapping function against extrinsic stimuli compared with hyaluronic acid (HA). First, we examined the penetration of sacran through stratum corneum (SC) with an impaired barrier function using immature reconstructed human epidermal equivalents. Sacran penetrates the SC to living cell layers of the epidermis, which suggested that sacran would attenuate adverse influences in keratinocytes caused by extracellular factors such as irritants or proinflammatory cytokines such as interleukin 1α (IL-1α). Sacran markedly reduced the cell damage induced by a nonionic detergent, sodium lauryl sulfate (SLS). Moreover, sacran restored the elevation of intracellular reactive oxygen species (ROS) levels stimulated by SLS and by IL-1α. These effects of sacran were superior to those of HA. In order to investigate the restoration effects of sacran, the influence of sacran on the physical properties of lipid bilayers was evaluated by measuring the order parameter using the ESR spin-labeling method. Because sacran failed to cause changes in the order parameters of liposomes and HaCaT keratinocytes, these results indicate that sacran does not interact with lipid bilayers although it restored changes in the order parameter caused by SLS. The sum of these results demonstrates that sacran reduces the influence of extracellular stimuli by its trapping effects. We conclude that the improving action of sacran is based on its trapping effect.


Assuntos
Cianobactérias/química , Dermatite Irritante , Queratinócitos/efeitos dos fármacos , Polissacarídeos/farmacologia , Substâncias Protetoras/farmacologia , Pele/efeitos dos fármacos , Dodecilsulfato de Sódio/efeitos adversos , Produtos Biológicos/farmacologia , Dermatite Atópica/prevenção & controle , Dermatite Irritante/metabolismo , Dermatite Irritante/prevenção & controle , Fármacos Dermatológicos/farmacologia , Epiderme/efeitos dos fármacos , Humanos , Interleucina-1alfa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Pele/citologia , Pele/metabolismo
14.
Appl Microbiol Biotechnol ; 101(6): 2343-2356, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27917435

RESUMO

Hydrophobins are amphipathic secretory proteins with eight conserved cysteine residues and are ubiquitous among filamentous fungi. In the fungus Aspergillus oryzae, the hydrophobin RolA and the polyesterase CutL1 are co-expressed when the sole available carbon source is the biodegradable polyester polybutylene succinate-co-adipate (PBSA). RolA promotes the degradation of PBSA by attaching to the particle surface, changing its structure and interacting with CutL1 to concentrate CutL1 on the PBSA surface. We previously reported that positively charged residues in RolA and negatively charged residues in CutL1 are cooperatively involved in the ionic interaction between RolA and CutL1. We also reported that hydrophobin RodA of the model fungus Aspergillus nidulans, which was obtained via an A. oryzae expression system, interacted via ionic interactions with CutL1. In the present study, phylogenetic and alignment analyses revealed that the N-terminal regions of several RolA orthologs contained positively charged residues and that the corresponding negatively charged residues on the surface of CutL1 that were essential for the RolA-CutL1 interaction were highly conserved in several CutL1 orthologs. A PBSA microparticle degradation assay, a pull-down assay using a dispersion of Teflon particles, and a kinetic analysis using a quartz crystal microbalance revealed that recombinant A. nidulans RodA interacted via ionic interactions with two recombinant A. nidulans cutinases. Together, these results imply that ionic interactions between hydrophobins and cutinases may be common among aspergilli and other filamentous fungi.


Assuntos
Aspergillus nidulans/genética , Aspergillus oryzae/genética , Hidrolases de Éster Carboxílico/química , Esterases/química , Proteínas Fúngicas/química , Regulação Fúngica da Expressão Gênica , Sequência de Aminoácidos , Aspergillus nidulans/metabolismo , Aspergillus oryzae/metabolismo , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/metabolismo , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Sequência Conservada , Esterases/genética , Esterases/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Filogenia , Polímeros/química , Polímeros/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Eletricidade Estática
15.
Biosci Biotechnol Biochem ; 81(7): 1363-1368, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28475418

RESUMO

Aspergillus oryzae hydrophobin RolA adheres to the biodegradable polyester polybutylene succinate-co-adipate (PBSA) and promotes PBSA degradation by interacting with A. oryzae polyesterase CutL1 and recruiting it to the PBSA surface. In our previous studies, we found that positively charged amino acid residues (H32, K34) of RolA and negatively charged residues (E31, D142, D171) of CutL1 are important for the cooperative ionic interaction between RolA and CutL1, but some other charged residues in the triple mutant CutL1-E31S/D142S/D171S are also involved. In the present study, on the basis of the 3D-structure of CutL1, we hypothesized that D30 is also involved in the CutL1-RolA interaction. We substituted D30 with serine and performed kinetic analysis of the interaction between wild-type RolA and the single mutant CutL1-D30S or quadruple mutant CutL1-D30S/E31S/D142S/D171S by using quartz crystal microbalance. Our results indicate that D30 is a novel residue involved in the ionic interaction between RolA and CutL1.


Assuntos
Ácido Aspártico/química , Aspergillus oryzae/química , Plásticos Biodegradáveis/química , Hidrolases de Éster Carboxílico/química , Proteínas Fúngicas/química , Polímeros/química , Motivos de Aminoácidos , Ácido Aspártico/metabolismo , Aspergillus oryzae/enzimologia , Sítios de Ligação , Plásticos Biodegradáveis/metabolismo , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Expressão Gênica , Interações Hidrofóbicas e Hidrofílicas , Cinética , Modelos Moleculares , Mutação , Polímeros/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Eletricidade Estática , Especificidade por Substrato
16.
World J Microbiol Biotechnol ; 33(4): 73, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28299556

RESUMO

Aneurinibacillus: sp. YR247 was newly isolated from the deep-sea sediment inside the Calyptogena community at a depth of 1171 m in Sagami Bay. The strain exhibited antifungal activity against the filamentous fungus Aspergillus brasiliensis NBRC9455. A crude extract prepared from the YR247 cells by ethanol extraction exhibited broad antimicrobial activities. The antifungal compound is stable at 4-70 °C and pH 2.0-12.0. After treatment with proteinase K, the antifungal activity was not detected, indicating that the antifungal compound of strain YR247 is a peptidic compound. Electrospray ionization mass spectrometry of the purified antifungal compound indicated that the peptidic compound has an average molecular weight of 1167.9. The molecular weight of the antifungal compound from strain YR247 is different from those of antimicrobial peptides produced by the related Aneurinibacillus and Bacillus bacteria. The antifungal peptidic compound from the deep-sea bacterium Aneurinibacillus sp. YR247 may be useful as a biocontrol agent.


Assuntos
Antifúngicos/farmacologia , Bacillales/isolamento & purificação , Peptídeos/farmacologia , Antifúngicos/isolamento & purificação , Aspergillus/efeitos dos fármacos , Bacillales/química , Bacillales/classificação , Sedimentos Geológicos/microbiologia , Peso Molecular , Peptídeos/isolamento & purificação , Filogenia , Espectrometria de Massas por Ionização por Electrospray
17.
Mol Microbiol ; 96(1): 14-27, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25588312

RESUMO

Hydrophobins are amphipathic proteins secreted by filamentous fungi. When the industrial fungus Aspergillus oryzae is grown in a liquid medium containing the polyester polybutylene succinate co-adipate (PBSA), it produces RolA, a hydrophobin, and CutL1, a PBSA-degrading cutinase. Secreted RolA attaches to the surface of the PBSA particles and recruits CutL1, which then condenses on the particles and stimulates the hydrolysis of PBSA. Here, we identified amino acid residues that are required for the RolA-CutL1 interaction by using site-directed mutagenesis. We quantitatively analyzed kinetic profiles of the interactions between RolA variants and CutL1 variants by using a quartz crystal microbalance (QCM). The QCM analyses revealed that Asp142, Asp171 and Glu31, located on the hydrophilic molecular surface of CutL1, and His32 and Lys34, located in the N-terminus of RolA, play crucial roles in the RolA-CutL1 interaction via ionic interactions. RolA immobilized on a QCM electrode strongly interacted with CutL1 (K(D) = 6.5 nM); however, RolA with CutL1 variants, or RolA variants with CutL1, showed markedly larger KD values, particularly in the interaction between the double variant RolA-H32S/K34S and the triple variant CutL1-E31S/D142S/D171S (K(D) = 78.0 nM). We discuss a molecular prototype model of hydrophobin-based enzyme recruitment at the solid-water interface.


Assuntos
Aminoácidos Acídicos/metabolismo , Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Sequência de Aminoácidos , Hidrolases de Éster Carboxílico/química , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Interações Hidrofóbicas e Hidrofílicas , Íons , Modelos Moleculares , Mutagênese Sítio-Dirigida , Poliésteres/metabolismo , Polímeros/metabolismo , Técnicas de Microbalança de Cristal de Quartzo
18.
Digestion ; 93(1): 47-52, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26789722

RESUMO

BACKGROUND: Superficial Barrett's esophageal adenocarcinoma (BEA) arising from short-segment Barrett's esophagus (SSBE) is visualized as a reddish lesion located on the right or anterior side wall of the esophagogastric mucosal junction (EGJ) and showing an elevated macroscopic appearance under conventional white light endoscopy (WLE). However, because the form and color are variable, misdiagnosis as reflux esophagitis or SSBE is frequent under WLE. The aim of this study is to clarify conventional WLE features of small superficial BEA. SUMMARY: We retrospectively analyzed 30 lesions ≤20 mm in diameter in 30 patients who underwent endoscopic mucosal resection or endoscopic submucosal dissection at Toranomon Hospital between 2002 and 2014. Mean age of patients with small superficial BEA arising from SSBE was 64.3 ± 11.2 years, and mean tumor size was 12.0 ± 4.8 mm. Small superficial BEA fell into the following 4 categories based on WLE features: EGJ polyp type, 43.3% (13 of 30 lesions); triangular SSBE type, 43.3% (13 of 30 lesions); cardiac erosion type, 10.0% (3 of 30 lesions); and unclassified or mixed type, 3.4% (1 of 30 lesions). EGJ polyp-type tumors were located on the right or anterior side wall of the EGJ, and no tumors showed invasion to the submucosal layer. On the other hand, triangular SSBE-type tumors were located anywhere in the EGJ, and 38.5% showed submucosal invasion (5 of 13 lesions). KEY MESSAGES: We consider this classification significantly contributes to the detection of small superficial BEA arising from SSBE under WLE.


Assuntos
Adenocarcinoma/patologia , Esôfago de Barrett/patologia , Neoplasias Esofágicas/patologia , Junção Esofagogástrica/patologia , Adenocarcinoma/complicações , Adenocarcinoma/cirurgia , Idoso , Esôfago de Barrett/complicações , Esôfago de Barrett/cirurgia , Estudos de Coortes , Dissecação , Neoplasias Esofágicas/complicações , Neoplasias Esofágicas/cirurgia , Esofagoscopia , Feminino , Gastroscopia , Hérnia Hiatal/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa/patologia , Mucosa/cirurgia , Invasividade Neoplásica , Estudos Retrospectivos , Carga Tumoral
19.
Biosci Biotechnol Biochem ; 78(10): 1693-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25273133

RESUMO

Hydrophobins are amphipathic secretory proteins with eight conserved cysteine residues and are ubiquitous among filamentous fungi. The Cys3-Cys4 and Cys7-Cys8 loops of hydrophobins are thought to form hydrophobic segments involved in adsorption of hydrophobins on hydrophobic surfaces. When the fungus Aspergillus oryzae is grown in a liquid medium containing the polyester polybutylene succinate-co-adipate (PBSA), A. oryzae produces hydrophobin RolA, which attaches to PBSA. Here, we analyzed the kinetics of RolA adsorption on PBSA by using a PBSA pull-down assay and a quartz crystal microbalance (QCM) with PBSA-coated electrodes. We constructed RolA mutants in which hydrophobic amino acids in the two loops were replaced with serine, and we examined the kinetics of mutant adsorption on PBSA. QCM analysis revealed that mutants with replacements in the Cys7-Cys8 loop had lower affinity than wild-type RolA for PBSA, suggesting that this loop is involved in RolA adsorption on PBSA.


Assuntos
Aminoácidos , Aspergillus oryzae , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Polímeros/química , Adsorção , Sequência de Aminoácidos , Proteínas Fúngicas/genética , Microesferas , Dados de Sequência Molecular , Mutação , Ligação Proteica
20.
Sci Rep ; 14(1): 2979, 2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38316822

RESUMO

Intentional binding refers to the subjective compression of the time interval between an action and its consequence. While intentional binding has been widely used as a proxy for the sense of agency, its underlying mechanism has been largely veiled. Bayesian causal inference (BCI) has gained attention as a potential explanation, but currently lacks sufficient empirical support. Thus, this study implemented various computational models to describe the possible mechanisms of intentional binding, fitted them to individual observed data, and quantitatively evaluated their performance. The BCI models successfully isolated the parameters that potentially contributed to intentional binding (i.e., causal belief and temporal prediction) and generally better explained an observer's time estimation than traditional models such as maximum likelihood estimation. The estimated parameter values suggested that the time compression resulted from an expectation that the actions would immediately cause sensory outcomes. Furthermore, I investigated the algorithm that realized this BCI and found probability-matching to be a plausible candidate; people might heuristically reconstruct event timing depending on causal uncertainty rather than optimally integrating causal and temporal posteriors. The evidence demonstrated the utility of computational modeling to investigate how humans infer the causal and temporal structures of events and individual differences in that process.


Assuntos
Percepção do Tempo , Humanos , Teorema de Bayes , Simulação por Computador , Intenção , Algoritmos
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