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1.
PLoS One ; 15(6): e0235341, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603354

RESUMO

Hydroxynitrile lyases (HNL's) belonging to the α/ß-hydrolase-fold superfamily evolved from esterases approximately 100 million years ago. Reconstruction of an ancestral hydroxynitrile lyase in the α/ß-hydrolase fold superfamily yielded a catalytically active hydroxynitrile lyase, HNL1. Several properties of HNL1 differ from the modern HNL from rubber tree (HbHNL). HNL1 favors larger substrates as compared to HbHNL, is two-fold more catalytically promiscuous for ester hydrolysis (p-nitrophenyl acetate) as compared to mandelonitrile cleavage, and resists irreversible heat inactivation to 35 °C higher than for HbHNL. We hypothesized that the x-ray crystal structure of HNL1 may reveal the molecular basis for the differences in these properties. The x-ray crystal structure solved to 1.96-Å resolution shows the expected α/ß-hydrolase fold, but a 60% larger active site as compared to HbHNL. This larger active site echoes its evolution from esterases since related esterase SABP2 from tobacco also has a 38% larger active site than HbHNL. The larger active site in HNL1 likely accounts for its ability to accept larger hydroxynitrile substrates. Site-directed mutagenesis of HbHNL to expand the active site increased its promiscuous esterase activity 50-fold, consistent with the larger active site in HNL1 being the primary cause of its promiscuous esterase activity. Urea-induced unfolding of HNL1 indicates that it unfolds less completely than HbHNL (m-value = 0.63 for HNL1 vs 0.93 kcal/mol·M for HbHNL), which may account for the ability of HNL1 to better resist irreversible inactivation upon heating. The structure of HNL1 shows changes in hydrogen bond networks that may stabilize regions of the folded structure.


Assuntos
Aldeído Liases/química , Aldeído Liases/genética , Domínio Catalítico , Cristalografia por Raios X/métodos , Esterases/química , Esterases/genética , Hevea/genética , Hevea/metabolismo , Modelos Moleculares , Estrutura Molecular , Mutagênese Sítio-Dirigida/métodos , Proteínas de Plantas/genética , Dobramento de Proteína , Especificidade por Substrato , Tabaco/genética , Tabaco/metabolismo
2.
PLoS One ; 15(7): e0228835, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649665

RESUMO

The mosquito Culex erythrothorax Dyar is a West Nile virus (WNV) vector that breeds in wetlands with emergent vegetation. Urbanization and recreational activities near wetlands place humans, birds and mosquitoes in close proximity, increasing the risk of WNV transmission. Adult Cx. erythrothorax abundance peaked in a wetland bordering the San Francisco Bay of California (USA) during the first 3 hours after sunset (5527 ± 4070 mosquitoes / trap night) while peak adult Culex tarsalis Coquillett abundance occurred during the subsequent 3 h period (83 ± 30 Cx. tarsalis). When insecticide resistance was assessed using bottle bioassay, Cx. erythrothorax was highly sensitive to permethrin, naled, and etofenprox insecticides compared to a strain of Culex pipiens that is susceptible to insecticides (LC50 = 0.35, 0.71, and 4.1 µg/bottle, respectively). The Cx. erythrothorax were 2.8-fold more resistant to resmethrin, however, the LC50 value was low (0.68 µg/bottle). Piperonyl butoxide increased the toxicity of permethrin (0.5 µg/bottle) and reduced knock down time, but a higher permethrin concentration (2.0 µg/bottle) did not have similar effects. Bulk mixed-function oxidase, alpha-esterase, or beta-esterase activities in mosquito homogenates were higher in Cx. erythrothorax relative to the Cx. pipiens susceptible strain. There was no difference in the activity of glutathione S-transferase between the two mosquito species and insensitive acetylcholine esterase was not detected. Larvicides that were applied to the site had limited impact on reducing mosquito abundance. Subsequent removal of emergent vegetation in concert with larvicide applications and reduced daily environmental temperature substantially reduced mosquito abundance. To control Cx. erythrothorax in wetlands, land managers should consider vegetation removal so that larvicide can efficiently enter the water. Vector control agencies may more successfully control adult viremic Cx. erythrothorax that enter nearby neighborhoods by applying adulticides during the 3 h that follow sunset.


Assuntos
Culex/fisiologia , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/toxicidade , Animais , California , Culex/crescimento & desenvolvimento , Esterases/metabolismo , Proteínas de Insetos/metabolismo , Larva/efeitos dos fármacos , Controle de Mosquitos , Permetrina/toxicidade , Butóxido de Piperonila/química , Piretrinas/toxicidade , Áreas Alagadas
3.
Int J Mol Sci ; 21(12)2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32604730

RESUMO

The recently emerged SARS-CoV-2 is the cause of the global health crisis of the coronavirus disease 2019 (COVID-19) pandemic. No evidence is yet available for CoV infection into hosts upon zoonotic disease outbreak, although the CoV epidemy resembles influenza viruses, which use sialic acid (SA). Currently, information on SARS-CoV-2 and its receptors is limited. O-acetylated SAs interact with the lectin-like spike glycoprotein of SARS CoV-2 for the initial attachment of viruses to enter into the host cells. SARS-CoV-2 hemagglutinin-esterase (HE) acts as the classical glycan-binding lectin and receptor-degrading enzyme. Most ß-CoVs recognize 9-O-acetyl-SAs but switched to recognizing the 4-O-acetyl-SA form during evolution of CoVs. Type I HE is specific for the 9-O-Ac-SAs and type II HE is specific for 4-O-Ac-SAs. The SA-binding shift proceeds through quasi-synchronous adaptations of the SA-recognition sites of the lectin and esterase domains. The molecular switching of HE acquisition of 4-O-acetyl binding from 9-O-acetyl SA binding is caused by protein-carbohydrate interaction (PCI) or lectin-carbohydrate interaction (LCI). The HE gene was transmitted to a ß-CoV lineage A progenitor by horizontal gene transfer from a 9-O-Ac-SA-specific HEF, as in influenza virus C/D. HE acquisition, and expansion takes place by cross-species transmission over HE evolution. This reflects viral evolutionary adaptation to host SA-containing glycans. Therefore, CoV HE receptor switching precedes virus evolution driven by the SA-glycan diversity of the hosts. The PCI or LCI stereochemistry potentiates the SA-ligand switch by a simple conformational shift of the lectin and esterase domains. Therefore, examination of new emerging viruses can lead to better understanding of virus evolution toward transitional host tropism. A clear example of HE gene transfer is found in the BCoV HE, which prefers 7,9-di-O-Ac-SAs, which is also known to be a target of the bovine torovirus HE. A more exciting case of such a switching event occurs in the murine CoVs, with the example of the ß-CoV lineage A type binding with two different subtypes of the typical 9-O-Ac-SA (type I) and the exclusive 4-O-Ac-SA (type II) attachment factors. The protein structure data for type II HE also imply the virus switching to binding 4-O acetyl SA from 9-O acetyl SA. Principles of the protein-glycan interaction and PCI stereochemistry potentiate the SA-ligand switch via simple conformational shifts of the lectin and esterase domains. Thus, our understanding of natural adaptation can be specified to how carbohydrate/glycan-recognizing proteins/molecules contribute to virus evolution toward host tropism. Under the current circumstances where reliable antiviral therapeutics or vaccination tools are lacking, several trials are underway to examine viral agents. As expected, structural and non-structural proteins of SARS-CoV-2 are currently being targeted for viral therapeutic designation and development. However, the modern global society needs SARS-CoV-2 preventive and therapeutic drugs for infected patients. In this review, the structure and sialobiology of SARS-CoV-2 are discussed in order to encourage and activate public research on glycan-specific interaction-based drug creation in the near future.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/virologia , Evolução Molecular , Interações entre Hospedeiro e Microrganismos/fisiologia , Pneumonia Viral/virologia , Receptores Virais/metabolismo , Internalização do Vírus , Acetilesterase/metabolismo , Animais , Betacoronavirus/genética , Sítios de Ligação , Linhagem Celular , Coronavirus/genética , Esterases , Transferência Genética Horizontal , Glicosaminoglicanos/metabolismo , Hemaglutininas Virais/genética , Humanos , Lectinas/metabolismo , Pandemias , Polissacarídeos , Receptores Virais/química , Ácidos Siálicos/química , Ácidos Siálicos/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/fisiologia , Torovirus , Proteínas Virais de Fusão/genética
5.
Bioresour Technol ; 315: 123845, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32707504

RESUMO

The main aim of this work was to study the allethrin binding interactions with esterase and its bioremediation potential using an isolated bacterial strain CW7, identified as Pseudomonas nitroreducens. The degradation conditions with strain CW7 were optimized using response surface methodology at pH 7.0, a temperature of 32 °C, and an inocula concentration of 150 mg·L-1, with 96% allethrin degradation observed over 7 days. The kinetic parameters qmax, Ks, and Ki were calculated to be 0.512 day-1, 4.97 mg·L-1, and 317.13 mg·L-1, respectively. Nine intermediate metabolites were identified after analysing the degradation products by gas chromatography-mass spectrometry. Strain CW7 effectively degraded a wide variety of pyrethroids as a carbon source. Molecular modeling, docking, and enzyme kinetics were used to investigate the binding pocket of the esterase containing amino acids such as alanine, arginine, valine, proline, cysteine, glycine, isoleucine, phenylalanine, serine, asparagine, and threonine, which play active roles in allethrin degradation.


Assuntos
Aletrinas , Histidina , Alanina , Arginina , Biodegradação Ambiental , Esterases , Glutamatos , Leucina , Lisina , Metionina , Pseudomonas , Serina , Tirosina
6.
J Am Mosq Control Assoc ; 36(1): 22-32, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32497474

RESUMO

In several insect species, resistance to pyrethroids and DDT (dichlorodiphenyltrichloroethane) is linked to point mutations in the voltage-gated sodium channel (VGSC) gene. Pyrethroid-based insecticides prolong the opening of sodium channels, causing paralysis known as a "knockdown" effect before mortality occurs. Point mutations in the VGSC gene result in decreased pyrethroid binding and reduced sensitivity to the insecticide-this resistance mechanism is known as knockdown resistance (kdr) as insects do not die but recover from paralysis with time. In Culex mosquito species loss of target site sensitivity to pyrethroids is linked to a number of substitutions, one of which is leucine (L) to phenylalanine (F) at residue 1014 (L1014F) in the VGSC gene. Here we report the identification of kdr-associated pyrethroid resistance and developing resistance in Cx. quinquefasciatus field collections from Collier County, FL. Evaluation of position 1014 of the VGSC in Cx. quinquefasciatus collections from 7 locations in Collier County, FL, revealed a wide range of genotypes from one part of the district to the other. Centers for Disease Control and Prevention bottle bioassay, linear regression analysis, and cage trial evaluations suggest that the L1014F mutation plays a role, at least in part, to the pyrethroid resistance status of Cx. quinquefasciatus collected in Collier County, FL. Furthermore, we identified resistance attributed to both oxidase and esterase activity, indicating that multiple mechanisms are responsible for pyrethroid resistance in Collier County Cx. quinquefasciatus.


Assuntos
Culex/genética , Esterases/genética , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Oxirredutases/genética , Piretrinas/farmacologia , Animais , Culex/efeitos dos fármacos , Culex/enzimologia , Esterases/metabolismo , Feminino , Florida , Oxirredutases/metabolismo
7.
J Oleo Sci ; 69(5): 467-477, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32378550

RESUMO

Esterases catalyze the hydrolysis of ester bonds in fatty acid esters with short-chain acyl groups. In the present study, thirty-seven bacterial isolates were isolated from soil contaminated with waste cooking oil, dairy waste etc. from Shimla and Solan district of H.P. Out of 37 isolates, the isolate RL-1, which gave maximum activity, was identified as Bacillus licheniformis MH061919. The optimization of various production parameters resulted in maximum activity at inoculum age of 24 h and inoculum size of 1.5% (v/v). Esterase gave considerable activity in production medium containing sodium chloride (0.5 % w/v), galactose (1%, w/v), coconut oil (2.0%, v/v) and beef extract (0.3%, w/v) at a temperature of 45℃ and pH 8.5.The enzyme production was enhanced by 3-fold after optimization of production parameters. Further, on optimizing reaction conditions, enzyme gave maximum activity at a temperature of 45℃ and pH 8.5. The para-nitrophenyl acetate (p-NPA) was found to be optimum substrate and metal ions and detergents have inhibitory effect on esterase activity.


Assuntos
Bacillus/enzimologia , Meios de Cultura/química , Técnicas de Cultura/métodos , Esterases/metabolismo , Bacillus/isolamento & purificação , Óleo de Coco , Galactose , Concentração de Íons de Hidrogênio , Nitrofenóis/metabolismo , Carne Vermelha , Cloreto de Sódio , Temperatura , Extratos de Tecidos
8.
Toxicol Appl Pharmacol ; 398: 115032, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32387182

RESUMO

BACKGROUND AND PURPOSE: Irinotecan-induced diarrhea (IID) results from intestinal damages by its active metabolite SN-38. Alleviation of these damages has focused on lowering luminal SN-38 concentrations. However, it is unclear if the enteric bioavailability of SN-38 is mostly dependent on luminal SN-38 concentrations. EXPERIMENTAL APPROACH: Irinotecan (50 mg/kg, i.p. once daily for 6 days) was administered to female wildtype FVB, Mdr1a (-/-), Mrp2 (-/-) and Bcrp1 (-/-) mice for pharmacokinetic (PK), toxicokinetic (TK) and biodistribution studies. Plasma PK/TK profiles and tissues drug distribution were determined after first or sixth daily doses, along with activities of blood and gut esterases and intestinal Ugts. Caco-2 cells and bile-cannulate mice were used to further investigate intestinal and biliary disposition of irinotecan and its metabolites. KEY RESULTS: Significant differences in IID severity were observed with the susceptible rank of Bcrp1(-/-) > wildtype FVB > Mdr1a(-/-) > Mrp2(-/-). This rank order did not correlate with biliary excretion rates of SN-38/SN-38G. Rather, the severity was best correlated (R = 0.805) with the intestinal ratio of Css SN-38/SN-38G, a measure of gut Ugt activity. On the contrary, IID was poorly correlated with plasma AUC ratio of SN-38/SN-38G (R = 0.227). Increased intestinal esterase activities due to repeated dosing and gut efflux transporter functionality are the other key factors that determine SN-38 enteric exposures. CONCLUSION AND IMPLICATIONS: Intestinal SN-38 exposure is mainly affected by intestinal Ugt activities and blood esterase activities, and strongly correlated with severity of IID. Modulating intestinal SN-38 concentration and gut Ugt expression should be the focus of future studies to alleviate IID.


Assuntos
Diarreia/induzido quimicamente , Glucuronosiltransferase/metabolismo , Intestinos/efeitos dos fármacos , Irinotecano/farmacologia , Animais , Antineoplásicos Fitogênicos , Área Sob a Curva , Bile/metabolismo , Sistema Biliar/efeitos dos fármacos , Sistema Biliar/metabolismo , Células CACO-2 , Linhagem Celular Tumoral , Diarreia/metabolismo , Esterases/metabolismo , Feminino , Humanos , Camundongos , Distribuição Tecidual/efeitos dos fármacos
9.
J Adhes Dent ; 22(3): 265-274, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32435767

RESUMO

PURPOSE: To investigate whether dental adhesives modified with polyacrylic acid copper iodide particles could inhibit esterase activity in vitro and the copper release rate from resin matrices, as well as the correlation between the two variables. MATERIALS AND METHODS: Different concentrations of copper iodide (0.1, 0.5 and 1.0 mg/ml) were incorporated into three commercially available adhesives representative of each type. Disk specimens (n = 3) were fabricated and incubated in cholesterol esterase and pseudo-cholinesterase solutions for 16 days (37°C, pH 7.0). The enzymatic activity and rate of copper release from resin matrices were evaluated at different 4, 8, 12, and 16 days with a UV/visible-light spectrophotometer. RESULTS: Increased copper release and reduced enzymatic activity were observed with higher concentrations of copper iodide (p < 0.001). Greater copper release with reduced enzymatic activity was also demonstrated at the earlier time periods with this relationship reversing over time (p < 0.001). A moderate negative correlation between the variables was evident (-0.441; p = 0.01). CONCLUSIONS: Adhesives containing copper iodide can inhibit esterase activity in a dose- and time-dependent manner. The correlation between the variables suggests that enzymatic activity may depend on the availability of copper.


Assuntos
Cimentos Dentários , Iodetos , Cobre , Esterases , Teste de Materiais
10.
Pestic Biochem Physiol ; 164: 100-114, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32284115

RESUMO

Understanding the mechanisms of pyrethroid resistance is essential to the effective management of pesticide resistance in Aphis glycines Matsumura (Hemiptera: Aphididae). We mined putative detoxifying enzyme genes in the draft genome sequence of A. glycines for cytochrome oxidase P450 (CYP), glutathione-S-transferase (GST) and esterases (E4 and carboxylesterases-CES). Aphids from clonal populations resistant to pyrethroids from three sites in Minnesota, USA, were screened against a diagnostic LC99 concentration of either λ-cyhalothrin or bifenthrin and detoxifying enzyme genes expression in survivors was analyzed by qPCR. Their expression profiles were compared relative to a susceptible clonal population. We found 61 CYP (40 full-length), seven GST (all full-length), seven E4 (five full-length) and three CES (two full-length) genes, including 24 possible pseudogenes. The detoxifying enzymes had different expression profiles across resistant aphid populations, possibly reflecting differences in the genetic background and pyrethroid selection pressures as the number of constitutively overexpressed detoxifying enzyme genes was correlated with the level of resistance. Our findings will strengthen the understanding of the pyrethroid resistance mechanisms in A. glycines.


Assuntos
Afídeos , Animais , Sistema Enzimático do Citocromo P-450 , Esterases , Soja
11.
Pestic Biochem Physiol ; 164: 130-139, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32284118

RESUMO

Protocols to determine metabolic resistance in ticks were mainly derived from reports published using mosquitoes and agriculturally important insects without prior standardization. In the present study, biochemical assays were standardized to quantify acaricide metabolizing enzymes in tick homogenates. Three variables viz., age, number of larvae and reaction time were optimized using reference susceptible IVRI-I and deltamethrin resistant IVRI-IV (Resistance Factor = 194) tick strains. The optimum conditions for estimation of general esterases were 10-15 day old 40 larvae with 15 mins reaction time, 15-20 day old 40 larvae with 20 mins reaction time for Glutathione S- transferase, while 10-15 day old 80 larvae with 5 mins reaction time for monooxygenase. The standardized protocols were further validated in multi acaricide resistant strain (IVRI-V) and in nine field isolates having variable resistant factors to different acaricides. In all the nine heterogeneous field isolates, a significant correlation (p < .05) between resistance to synthetic pyrethroids and over-expression of esterases and monooxygenase was noticed. Similarly, esterases and GST activities were significantly correlated with resistance to organophosphates. The details of the assay protocol are explained for adoption in different laboratories.


Assuntos
Acaricidas , Piretrinas , Rhipicephalus , Animais , Esterases , Glutationa Transferase , Resistência a Inseticidas , Larva , Oxigenases de Função Mista
12.
Rev Med Suisse ; 16(689): 675-678, 2020 Apr 08.
Artigo em Francês | MEDLINE | ID: mdl-32270933

RESUMO

Hereditary angioedema type 1 and 2 are due to a deficiency in C1--esterase inhibitor. This molecule inhibits the generation of bradykinin, a potent inflammatory mediator that increases vascular permeability. Upon accumulation of bradykinin, patients affected develop painful subcutaneous or submucosal edemas that last for several days. In case the upper airways are affected, there is risk of suffocation. This type of angioedema does not respond to antihistamines, cortico-steroids or epinephrine. Management of angioedema attacks consists in injecting C1-esterase inhibitor concentrate or icatibant, a bradykinin receptor B2 antagonist. Preventive measures aim at reducing the frequency and the severity of angioedema attacks. Inhibition of -plasma kallikrein by lanadelumab, a monoclonal antibody adminis-tered subcutaneously, is effective and well tolerated.


Assuntos
Angioedema , Angioedemas Hereditários/enzimologia , Proteína Inibidora do Complemento C1/uso terapêutico , Esterases/antagonistas & inibidores , Angioedemas Hereditários/tratamento farmacológico , Anticorpos Monoclonais , Bradicinina/análogos & derivados , Bradicinina/uso terapêutico , Inativadores do Complemento/uso terapêutico , Humanos
13.
Proc Natl Acad Sci U S A ; 117(13): 7122-7130, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32170022

RESUMO

ß-mannans and xylans are important components of the plant cell wall and they are acetylated to be protected from degradation by glycoside hydrolases. ß-mannans are widely present in human and animal diets as fiber from leguminous plants and as thickeners and stabilizers in processed foods. There are many fully characterized acetylxylan esterases (AcXEs); however, the enzymes deacetylating mannans are less understood. Here we present two carbohydrate esterases, RiCE2 and RiCE17, from the Firmicute Roseburia intestinalis, which together deacetylate complex galactoglucomannan (GGM). The three-dimensional (3D) structure of RiCE17 with a mannopentaose in the active site shows that the CBM35 domain of RiCE17 forms a confined complex, where the axially oriented C2-hydroxyl of a mannose residue points toward the Ser41 of the catalytic triad. Cavities on the RiCE17 surface may accept galactosylations at the C6 positions of mannose adjacent to the mannose residue being deacetylated (subsite -1 and +1). In-depth characterization of the two enzymes using time-resolved NMR, high-performance liquid chromatography (HPLC), and mass spectrometry demonstrates that they work in a complementary manner. RiCE17 exclusively removes the axially oriented 2-O-acetylations on any mannose residue in an oligosaccharide, including double acetylated mannoses, while the RiCE2 is active on 3-O-, 4-O-, and 6-O-acetylations. Activity of RiCE2 is dependent on RiCE17 removing 2-O-acetylations from double acetylated mannose. Furthermore, transacetylation of oligosaccharides with the 2-O-specific RiCE17 provided insight into how temperature and pH affects acetyl migration on manno-oligosaccharides.


Assuntos
Clostridiales/enzimologia , Esterases/metabolismo , Mananas/metabolismo , Esterases/química , Picea , Conformação Proteica , Especificidade por Substrato
14.
Ecotoxicol Environ Saf ; 195: 110517, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32220793

RESUMO

Phthalate esters (PAEs), a class of toxic anthropogenic compounds, have been predominantly used as additives or plasticizers, and great concern and interests have been raised regarding its environmental behavior and degradation mechanism. In the present study, a bacterial consortium consisting of Microbacterium sp. PAE-1 and Pandoraea sp. PAE-2 was isolated by the enrichment method, which could degrade dibutyl phthalate (DBP) completely by biochemical cooperation. DBP was converted to phthalic acid (PA) via monobutyl phthalate (MBP) by two sequential hydrolysis steps in strain PAE-1, and then PA was further degraded by strain PAE-2. Strain PAE-1 could hydrolyze many dialkyl Phthalate esters (PAEs) including dimethyl, diethyl, dibutyl, dipentyl, benzyl butyl, dihexyl, di-(2-ethyhexyl) and their corresponding monoalkyl PAEs. Two esterase genes named dpeH and mpeH, located in the same transcription unit, were cloned from strain PAE-1 by the shotgun method and heterologously expressed in Escherichia. coli (DE3). The Km and kcat values of DpeH for DBP were 9.60 ± 0.97 µM and (2.72 ± 0.06) × 106 s-1, while those of MpeH for MBP were 18.61 ± 2.00 µM and (5.83 ± 1.00) × 105 s-1, respectively. DpeH could only hydrolyze dialkyl PAEs to the corresponding monoalkyl PAEs, which were then hydrolyzed to PA by MpeH. DpeH shares the highest similarity (53%) with an alpha/beta hydrolase from Microbacterium sp. MED-G48 and MpeH shows only 25% identity with a secreted lipase from Trichophyton benhamiae CBS 112371, indicating that DpeH and MpeH are two novel hydrolases against PAEs.


Assuntos
Dibutilftalato/análise , Poluentes Ambientais/análise , Esterases/genética , Consórcios Microbianos/efeitos dos fármacos , Plastificantes/análise , Actinobacteria/efeitos dos fármacos , Actinobacteria/enzimologia , Burkholderiaceae/efeitos dos fármacos , Burkholderiaceae/enzimologia , Dibutilftalato/química , Poluentes Ambientais/química , Genes Bacterianos , Hidrólise , Lipase/genética , Consórcios Microbianos/genética , Ácidos Ftálicos/análise , Plastificantes/química
15.
Plant Sci ; 292: 110384, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32005389

RESUMO

Salicylic acid (SA) plays an important role in the response of plants to abiotic stresses. Starvation stress affects plant cell metabolic activities, which further limits the normal growth and development of plants. It was reported that SA might play a regulatory role in the process of plant against starvation stress, but the mechanism involved in this process is still unclear. Thus, in this study, the transgenic plants overexpressing a SA binding protein 2 (SABP2) gene were exposed to starvation stress and the transgenic lines showed starvation-tolerant phenotype. Compared with wild-type (WT) plants, transgenic plants showed better growth status under poor-nutrition stress. Transgenic plants also showed more vigorous roots than WT plants. Physiological tests indicated that the transgenic plants showed higher relative water content (RWC), chlorophyll content, photosynthetic capacity, endogenous SA content, and lower ROS level compared to WT plants. Transcriptome analysis of tobacco plants identified 3, 748 differentially expressed genes (DEGs) between transgenic and WT plants under starvation stress. These DEGs are mainly involved in glycolysis/gluconeogenesis pathway group, MAPK signaling pathway group and plant hormone signal transduction pathway group. As determined by qPCR, up-regulated expression of fifteen genes such as abscisic acid receptor PYR1-like gene (NtPYR1-like), bidirectional sugar transporter N3-like gene (NtSWEETN3-like) and superoxide dismutase [Fe] chloroplastic-like gene (NtFeSOD-like), etc., was observed in transgenic plants under poor-nutrition stress which was in accordance with RNA-sequencing results. The modified pathways involved in plant hormone signaling are thought to be at least one of the main causes of the increased starvation tolerance of transgenic tobacco plants with altered SA homeostasis.


Assuntos
Esterases/genética , Regulação da Expressão Gênica de Plantas , Nutrientes/metabolismo , Proteínas de Plantas/genética , Ácido Salicílico/metabolismo , Tabaco/fisiologia , Esterases/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Estresse Fisiológico/genética , Tabaco/genética
16.
Nat Commun ; 11(1): 1026, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32094331

RESUMO

Structural and functional studies were conducted of the glucuronoyl esterase (GE) from Cerrena unicolor (CuGE), an enzyme catalyzing cleavage of lignin-carbohydrate ester bonds. CuGE is an α/ß-hydrolase belonging to carbohydrate esterase family 15 (CE15). The enzyme is modular, comprised of a catalytic and a carbohydrate-binding domain. SAXS data show CuGE as an elongated rigid molecule where the two domains are connected by a rigid linker. Detailed structural information of the catalytic domain in its apo- and inactivated form and complexes with aldouronic acids reveal well-defined binding of the 4-O-methyl-a-D-glucuronoyl moiety, not influenced by the nature of the attached xylo-oligosaccharide. Structural and sequence comparisons within CE15 enzymes reveal two distinct structural subgroups. CuGE belongs to the group of fungal CE15-B enzymes with an open and flat substrate-binding site. The interactions between CuGE and its natural substrates are explained and rationalized by the structural results, microscale thermophoresis and isothermal calorimetry.


Assuntos
Domínio Catalítico , Esterases/metabolismo , Proteínas Fúngicas/metabolismo , Ácido Glucurônico/metabolismo , Polyporales/enzimologia , Carboidratos , Parede Celular/metabolismo , Cristalografia por Raios X , Esterases/isolamento & purificação , Esterases/ultraestrutura , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/ultraestrutura , Hidrólise , Lignina/metabolismo , Estrutura Secundária de Proteína , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Espalhamento a Baixo Ângulo , Relação Estrutura-Atividade , Especificidade por Substrato , Difração de Raios X
17.
Sci Rep ; 10(1): 1299, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992834

RESUMO

The majority of carotenoids in petals are xanthophylls and most of these xanthophylls are esterified with fatty acids. Although petunia (Petunia x hybrida) is an important ornamental plant, it cannot accumulate enough carotenoids to have deep-yellow flowers. Our previous study suggested that low esterification activity causes low carotenoid accumulation in petunia corollas. Here, we introduced xanthophyll esterase (XES) from the petals of Ipomoea obscura, tomato (Solanum lycopersicum), and marigold (Tagetes erecta) into a pale-yellow-flowered cultivar of petunia to see whether these affect carotenoid accumulation in petunia corollas. Carotenoid contents and the proportions of esterified xanthophylls were elevated in the corollas of XES-overexpressing (XES-OX) transformants. Expression analysis showed that the transcript levels of endogenous carotenoid biosynthetic genes, which included geranylgeranyl diphosphate synthase 2, ζ-carotene desaturase, and lycopene ß-ring cyclase in corolla tubes were upregulated in XES-OX plants. In addition, we discovered a difference in the composition of esterified xanthophylls among XES-OX plants, which may be caused by differences in the substrate specificity of their respective XESs. We conclude that esterification is an important process for carotenoid accumulation and XES is a useful tool for the quantitative and qualitative control of carotenoid accumulation in petals.


Assuntos
Esterases , Flores , Expressão Gênica , Petunia , Pigmentação , Proteínas de Plantas , Plantas Geneticamente Modificadas , Xantofilas/metabolismo , Esterases/biossíntese , Esterases/genética , Flores/enzimologia , Flores/genética , Petunia/enzimologia , Petunia/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética
18.
Carbohydr Polym ; 230: 115613, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887935

RESUMO

Targeted and sensitive drug release at the colitis site is critical for the effective therapy of ulcerative colitis and reduction of side effects from the drug. Herein, we used 3,3'-dithiodipropionic acid (DTPA) to covalently link quercetin (Qu) and glyceryl caprylate-caprate (Gcc) via ester bonds to prepare Qu-SS-Gcc lipid nanoparticles (Qu-SS-Gcc LNPs). Dexamethasone (Dex) was used as a model drug, and chitosan (CSO) was modified on the surface of Qu-SS-Gcc LNPs to obtain CSO-modified Dex-loaded Qu-SS-Gcc LNPs (CSO/Dex/LNPs). The encapsulation efficiency and drug loading of CSO/Dex/LNPs were 93.1 % and 8.1 %, respectively. The in vitro release results showed that CSO/Dex/LNPs had esterase-responsive characteristics and could release the drug rapidly in esterase-containing artificial intestinal fluid. A human colorectal adenocarcinoma cell (Caco-2) monolayer was used as the intestinal cell barrier model. Transmembrane resistance measurements and permeation experiments showed that CSO/Dex/LNPs had a protective effect on the lipopolysaccharide (LPS)-stimulated Caco-2 cell monolayer and increased the expression of E-cadherin in LPS-stimulated Caco-2 cells. Moreover, CSO/Dex/LNPs could significantly reduce the expression of the inflammatory factors TNF-α, IL-6 and NO in LPS-stimulated RAW 264.7 cells. The ulcerative colitis mouse model was constructed by using C57BL/6 mice. The in vivo distribution results showed that CSO/Dex/LNPs had colon-targeting effects and strong retention ability in the colons of mice with colitis. The results also showed that CSO/Dex/LNPs had better anti-inflammatory effects than free Dex, which could reduce colonic atrophy, reduce histomorphological changes and increase the expression of E-cadherin in the colon. Furthermore, the expression levels of TNF-α, IL-6 and NO in the CSO/Dex/LNP-treated group were 37.4 %, 35.5 % and 33.2 % of those in mice with colitis, respectively.


Assuntos
Caprilatos/química , Quitosana/análogos & derivados , Colite Ulcerativa/tratamento farmacológico , Portadores de Fármacos/química , Nanopartículas/química , Polímeros Responsivos a Estímulos/química , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/uso terapêutico , Células CACO-2 , Colo/efeitos dos fármacos , Colo/metabolismo , Reagentes para Ligações Cruzadas/química , Citocinas/genética , Citocinas/metabolismo , Dexametasona/administração & dosagem , Dexametasona/uso terapêutico , Portadores de Fármacos/efeitos adversos , Esterases/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/efeitos adversos , Óxido Nítrico/metabolismo , Quercetina/administração & dosagem , Quercetina/química , Quercetina/uso terapêutico , Células RAW 264.7
19.
PLoS One ; 15(1): e0227267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31931513

RESUMO

The relevant information about the impacts caused by presence of emerging pollutants in mixtures on the ecological environment, especially on the more vulnerable compartments such as activated sludge (AS) is relatively limited. This study investigated the effect of ibuprofen (IBU) and triclosan (TCS), alone and in combination to the performance and enzymatic activity of AS bacterial community. The assays were carried out in a pilot AS reactor operating for two-weeks under continuous dosage of pollutants. The microbial activity was tracked by measuring oxygen uptake rate, esterase activity, oxidative stress and antioxidant enzyme activities. It was found that IBU and TCS had no acute toxic effects on reactor biomass concentration. TCS led to significant decrease of COD removal efficiency, which dropped from 90% to 35%. Continuous exposure to IBU, TCS and their mixtures increased the activities of glutathione s-transferase (GST) and esterase as a response to oxidative damage. A high increase in GST activity was associated with non-reversible toxic damage while peaks of esterase activity combined with moderate GST increase were attributed to an adaptive response.


Assuntos
Bactérias/enzimologia , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental/efeitos dos fármacos , Reatores Biológicos/microbiologia , Poluentes Químicos da Água/toxicidade , Bactérias/efeitos dos fármacos , Biomassa , Esterases/metabolismo , Glutationa Transferase/metabolismo , Ibuprofeno/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/metabolismo , Triclosan/toxicidade , Águas Residuárias/química , Águas Residuárias/toxicidade , Purificação da Água/métodos
20.
Ecotoxicol Environ Saf ; 190: 110148, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31911388

RESUMO

Phthalate esters have raised public concerns owing to their effects on the environment and human health. We identified a novel phthalate-degrading hydrolase, EstJ6, from a metagenomic library using function-driven screening. Phylogenetic analysis indicated that EstJ6 is a member of family IV esterases. EstJ6 hydrolyzed various dialkyl and monoalkyl phthalate esters, and exhibited high hydrolytic activity (128 U/mg) toward dibutyl phthalate at 40 °C and pH 7.5. EstJ6 hydrolyzed not only common phthalate esters with simple side chains but also diethylhexyl phthalate and monoethylhexyl phthalate, which have complex and long side chains. Site-directed mutagenesis indicated that the catalytic triad residues of EstJ6 consists of Ser146, Glu240, and His270. EstJ6 is therefore a promising biodegradation enzyme, and our study illustrates the advantages of a metagenomic approach in identifying enzyme-coding genes for agricultural, food, and biotechnological applications.


Assuntos
Biodegradação Ambiental , Hidrolases/metabolismo , Ácidos Ftálicos/metabolismo , Dibutilftalato/metabolismo , Dietilexilftalato/metabolismo , Esterases/metabolismo , Ésteres/química , Biblioteca Gênica , Hidrolases/genética , Hidrólise , Metagenoma , Filogenia , Solo
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