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1.
Mol Biol Rep ; 51(1): 458, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38551694

RESUMEN

Arterial hypertension is characterized by systolic pressure ≥ 140 mmHg and/or diastolic pressure ≥ 90 mmHg and its treatment consists of the use of antihypertensive drugs, as losartan and hydrochlorothiazide. Blood pressure is regulated by angiotensin-converting enzyme (ACE) and polymorphisms in the ACE gene are associated to a greater predisposition to hypertension and response to treatment. The aim of this study was to evaluate the association of genetic polymorphisms of ACE rs4363, rs4291 and rs4335 and the response to antihypertensive drugs in hypertensive patients from Ouro Preto/MG, Brazil. A case-control study was carried out with 87 hypertensive patients being treated with losartan and 75 with hydrochlorothiazide, who answered a questionnaire and had blood samples collected. Biochemical analyzes were performed on serum using UV/Vis spectrophotometry and identification of ACE variants rs4363, rs4291 and rs4335 was performed by real-time PCR using the TaqMan® system. Univariate logistic regression test was performed to compare categorical data in STATA 13.0 software. The results showed that there was an influence of ACE polymorphisms on the response to losartan, demonstrating that AT or TT genotypes of rs4291 were more frequent in the group of controlled AH (54.9%), indicating that these individuals are 2.8 times more likely to of being controlled AH (95% CI 1.12-6.80, p. =0.026) compared to those with AA genotype. In contrast, no influence of ACE polymorphisms on the response to hydrochlorothiazide was observed. In conclusion, the presence of the T allele of the rs4291 variant was associated to controled blood pressure when losartan was used as an antihypertensive agent. These results show the importance of pharmacogenetic studies to detect genetic characteristics, enabling therapeutic individuality and reducing costs for the healthcare system.


Asunto(s)
Antihipertensivos , Hipertensión , Losartán , Peptidil-Dipeptidasa A , Humanos , Antihipertensivos/uso terapéutico , Antihipertensivos/farmacología , Presión Sanguínea/genética , Estudios de Casos y Controles , Hidroclorotiazida/uso terapéutico , Hidroclorotiazida/farmacología , Hipertensión/tratamiento farmacológico , Hipertensión/genética , Losartán/uso terapéutico , Losartán/farmacología , Polimorfismo de Nucleótido Simple/genética , Peptidil-Dipeptidasa A/genética
2.
Exp Appl Acarol ; 93(2): 353-367, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38888667

RESUMEN

Direct and indirect ecological interactions, environmental factors, and the phenology of host plants can shape the way mites interact. These relationships interfere with species occurrence and consequently alter the structure and stability of the intraplant community. As predatory mites act as regulators of herbivorous mites, we hypothesized that these mites may occupy a central position in a network of interactions among mite species associated with mango trees, and the occurrence of these species is mediated by environmental variables and the phenological stage of the host plant. We evaluated the global structure of the interaction network of mites associated with individual Mangifera indica plants and analyzed the interspecific relationships of the species using an undirected Bayesian network approach. Additionally, we observed a correlation between mite population density and plant phenological stage. Environmental variables, such as average monthly temperature, monthly precipitation, and average monthly relative humidity at different sampling date were used in the correlation analysis. The modularity at the mite-plant network level showed a low specialization index H2 = 0.073 (generalist) and high robustness (R = 0.93). Network analysis revealed that Amblyseius largoensis, Bdella ueckermanni, Parapronematus acaciae, and Tuckerella ornata occupied central positions in the assembly of mites occurring on mango trees. Environmental variables, average monthly temperature, and monthly precipitation were correlated with the occurrence of Brachytydeus formosa, Cisaberoptus kenyae, Oligonychus punicae, T. ornata, and Vilaia pamithus. We also observed a correlation between the plant phenological stage and population densities of Neoseiulus houstoni, O. punicae, P. acaciae, and V. pamithus.


Asunto(s)
Mangifera , Ácaros , Mangifera/parasitología , Animales , Ácaros/fisiología , Densidad de Población , Cadena Alimentaria , Teorema de Bayes
3.
Mol Biol Rep ; 50(2): 1487-1497, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36507965

RESUMEN

INTRODUCTION: The genetic component, including genes and their variants, plays a significant role in the pathophysiology of arterial hypertension (AH). Thus, clinical, epidemiological and genetic studies have been carried out to improve the understanding of disease mechanisms, improve diagnostic quality and contribute to prevention. OBJECTIVE: To determine the association of risk factors, biochemical parameters and different ACE gene polymorphisms with AH. METHOD: The case-control study was carried out in the population of Ouro Preto, Brazil. The subjects answered a questionnaire containing clinical and sociodemographic data. The ACE gene polymorphisms rs4291, rs4363 and rs4335 were evaluated by real time-polymerase chain reaction (real-time PCR) in 310 people (155 hypertensive and 155 normotensive patients), in addition to biochemical parameters. A multivariate logistic regression model was used to identify factors associated with AH. Analysis of continuous variables was performed using the Kruskal-Wallis test to assess significance between groups and Dunn's post-test for multiple comparisons. RESULTS: The results showed that AH was associated with age, education, smoking, obesity and high levels of triglycerides, sodium, glucose and uric acid. Regarding the biochemical parameters, in hypertensive patients, the rs4363 and rs4335 polymorphisms were associated with high levels of triglycerides, urea and glucose; the rs4291 polymorphism was associated with elevated urea and glucose levels. No association was detected between SNPs and HA. CONCLUSION: AH was associated with socioeconomic status, lifestyle habits and biochemical parameters. ACE polymorphisms may have influenced the levels of triglycerides, urea and glucose in hypertensive patients.


Asunto(s)
Hipertensión , Peptidil-Dipeptidasa A , Humanos , Angiotensinas , Estudios de Casos y Controles , Genotipo , Hipertensión/genética , Hipertensión/tratamiento farmacológico , Peptidil-Dipeptidasa A/genética , Polimorfismo de Nucleótido Simple/genética , Triglicéridos
4.
Anticancer Drugs ; 33(1): e389-e397, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34486536

RESUMEN

The treatment of bladder cancer remains a challenge in clinical practice. Different chemotherapeutic protocols can be used; however, it is common to observe tumor recurrence and secondary effects that result in toxicity. Doxorubicin (DOX), one of the most effective anticancer agents used to treat bladder cancer, can cause chronic cardiotoxicity, limiting its use in clinical practice. Resveratrol (RES), a natural product with potential antitumor activity against bladder cancer, is associated with rapid metabolism and low bioavailability and needs to be combined with chemotherapeutic drugs to improve its use. Our study aimed to assess the therapeutic effect of a low concentration of DOX (2 µM) in combination with RES (150, 200 and 250 µM) on two bladder cancer cell lines. We investigated the mechanism of interaction between the drugs by performing cytotoxicity, clonogenic, oxidative stress, cell migration, cell morphology and nuclear division index (NDI) assays. Cytotoxicity evaluation revealed an additive interaction between RES and DOX for both cell lines. Additionally, the results of cell colony formation, oxidative stress, cell migration, cell morphology and NDI assays showed that a combination of DOX and RES was more effective than RES or DOX alone. In conclusion, a low concentration of DOX combined with RES could potentiate the antitumor effects of the drugs on bladder cancer cells, thus overcoming the secondary effects caused by DOX and the low bioavailability of resveratrol.


Asunto(s)
Antineoplásicos/farmacología , Doxorrubicina/farmacología , Resveratrol/farmacología , Neoplasias de la Vejiga Urinaria/patología , Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxorrubicina/administración & dosificación , Humanos , Estrés Oxidativo/efectos de los fármacos , Resveratrol/administración & dosificación , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Molecules ; 27(17)2022 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-36080291

RESUMEN

The partitioning of the molecular mechanics (MM) energy in calculations involving biomolecular systems is important to identify the source of major stabilizing interactions, e.g., in ligand-protein interactions, or to identify residues with considerable contributions in hybrid multiscale calculations, i.e., quantum mechanics/molecular mechanics (QM/MM). Here, we describe Energy Split, a software program to calculate MM energy partitioning considering the AMBER Hamiltonian and parameters. Energy Split includes a graphical interface plugin for VMD to facilitate the selection of atoms and molecules belonging to each part of the system. Energy Split is freely available at or can be easily installed through the VMD Store.


Asunto(s)
Simulación de Dinámica Molecular , Teoría Cuántica , Ligandos , Fenómenos Físicos , Programas Informáticos
6.
Int J Equity Health ; 20(1): 183, 2021 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-34391416

RESUMEN

BACKGROUND: The determinants of access to immunizers are still poorly understood, leading to questions about which criteria were considered in this distribution. Given the above, the present study aimed to analyze the determinants of access to the SARS-CoV-2 vaccine by different countries. METHODS: The study covered 189 countries using data from different public databases, and collected until February 19, 2021. We used eight explanatory variables: gross domestic product (GDP), extreme poverty, human development index (HDI), life expectancy, median age, coronavirus disease 2019 (COVID-19) cases, COVID-19 tests, and COVID-19 deaths. The endogenous variables were total vaccine doses, vaccine doses per thousand, and days of vaccination. The structural equation modeling (SEM) technique was applied to establish the causal relationship between the country's COVID-19 impact, socioeconomic variables, and vaccine access. To support SEM, we used confirmatory factor analysis, t-test, and Pearson's correlation. RESULTS: We collected the sample on February 19, and to date, 80 countries (42.1%) had already received a batch of immunizers against COVID-19. The countries with first access to the vaccine (e.g., number of days elapsed since they took the first dose) were the United Kingdom (68), China (68), Russia (66), and Israel (62). The countries receiving the highest doses were the United States, China, India, and Israel. The countries with extreme poverty had lower access to vaccines and the richer countries gained priority access. Countries most affected by COVID (deaths and cases) also received immunizers earlier and in greater volumes. Unfortunately, similar to other vaccines, indicators, such as income, poverty, and human development, influence vaccines' access. Thus affecting the population of vulnerable and less protected countries. Therefore, global initiatives for the equitable distribution of COVID need to be discussed and encouraged. CONCLUSIONS: Determinants of vaccine distribution consider the impact of the disease in the country and are also affected by favorable socioeconomic indicators. The COVID-19 vaccines need to be accessible to all affected countries, regardless of their social hands.


Asunto(s)
Vacunas contra la COVID-19 , Salud Global , Asignación de Recursos para la Atención de Salud , Accesibilidad a los Servicios de Salud , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19/provisión & distribución , Asignación de Recursos para la Atención de Salud/métodos , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Humanos , Factores Socioeconómicos
7.
Biofouling ; 37(1): 96-108, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33508968

RESUMEN

Biofilms play an important role in health, being associated with >80% of all microbial infections in the body and in the development of antibiotic resistance. Research in this field has continuously produced large volumes of data. Being able to handle all this information will be paramount for progress in this field. However, this places a heavy burden on the development of strategies to gather, organize and make this information available in a way that can be readily and effectively used by those requiring it. Lately, efforts towards this goal have been reported, particularly with the development of Quorumpeps, BiofOmics, BaAMPs, QSPpred, dPABBs, aBiofilm and the Biofilms Structural Database. This work reviews these databases and highlights their applicability and potential, while stressing some of the challenges for the coming years in database development and usage brought about by the use of big data and machine learning.


Asunto(s)
Biopelículas , Percepción de Quorum , Antibacterianos/farmacología , Farmacorresistencia Microbiana
8.
Molecules ; 26(9)2021 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-33946907

RESUMEN

Biofilms are aggregates of microorganisms anchored to a surface and embedded in a self-produced matrix of extracellular polymeric substances and have been associated with 80% of all bacterial infections in humans. Because bacteria in biofilms are less amenable to antibiotic treatment, biofilms have been associated with developing antibiotic resistance, a problem that urges developing new therapeutic options and approaches. Interfering with quorum-sensing (QS), an important process of cell-to-cell communication by bacteria in biofilms is a promising strategy to inhibit biofilm formation and development. Here we describe and apply an in silico computational protocol for identifying novel potential inhibitors of quorum-sensing, using CviR-the quorum-sensing receptor from Chromobacterium violaceum-as a model target. This in silico approach combines protein-ligand docking (with 7 different docking programs/scoring functions), receptor-based virtual screening, molecular dynamic simulations, and free energy calculations. Particular emphasis was dedicated to optimizing the discrimination ability between active/inactive molecules in virtual screening tests using a target-specific training set. Overall, the optimized protocol was used to evaluate 66,461 molecules, including those on the ZINC/FDA-Approved database and to the Mu.Ta.Lig Virtual Chemotheca. Multiple promising compounds were identified, yielding good prospects for future experimental validation and for drug repurposing towards QS inhibition.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Descubrimiento de Drogas , Modelos Moleculares , Percepción de Quorum/efectos de los fármacos , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/química , Sitios de Unión , Descubrimiento de Drogas/métodos , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Estructura Molecular , Unión Proteica , Relación Estructura-Actividad
9.
Waste Manag Res ; 39(11): 1341-1355, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33691535

RESUMEN

Construction and demolition waste (CDW) substantially contributes to environmental degradation because of its intrinsic characteristics of fast and high generation volume, low recycling rate, and low revenue margins. A systemic problem is that recycling facilities are not usually a part of a reverse supply chain (RSC) specific for CDW. This makes the recovery process costs prohibitive, especially where companies are unable to receive and process large volumes of waste continuously. This paper presents a systematic analysis of the extant literature and utilizes the results accrued to develop a conceptual RSC model for CDW. In so doing, the research seeks to provide clarity on this phenomenon, while simultaneously stimulating wider academic discourse and further research endeavours. A mixed philosophies epistemological design was adopted using both interpretavism and constructivism to undertake a qualitative systematic analysis of the literature. A process diagram was produced to represent the conceptual model (CM) and thematically group the nodes into three key swim lanes that delineate the boundaries between distribution, manufacturing, and sourcing and warehousing processes. Within each swim lane, stakeholders were incorporated as key actors. A further layer of nuanced complexity was added to illustrate the key actors involved in the process, government strategies, and activity flow paths. This novel CM offers both practical and theoretical contributions to existing knowledge and signposts a future research direction. Such work will demystify reverse logistics for managing CDW, and assist government policy-makers to develop informed policies that reduce the negative environmental impact of construction activities.


Asunto(s)
Industria de la Construcción , Administración de Residuos , Materiales de Construcción , Modelos Teóricos , Reciclaje
10.
Angew Chem Int Ed Engl ; 60(18): 10064-10072, 2021 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-33599093

RESUMEN

In recent years, extensive sequencing and annotation of bacterial genomes has revealed an unexpectedly large number of secondary metabolite biosynthetic gene clusters whose products are yet to be discovered. For example, cyanobacterial genomes contain a variety of gene clusters that likely incorporate fatty acid derived moieties, but for most cases we lack the knowledge and tools to effectively predict or detect the encoded natural products. Here, we exploit the apparent absence of a functional ß-oxidation pathway in cyanobacteria to achieve efficient stable-isotope-labeling of their fatty acid derived lipidome. We show that supplementation of cyanobacterial cultures with deuterated fatty acids can be used to easily detect natural product signatures in individual strains. The utility of this strategy is demonstrated in two cultured cyanobacteria by uncovering analogues of the multidrug-resistance reverting hapalosin, and novel, cytotoxic, lactylate-nocuolin A hybrids-the nocuolactylates.


Asunto(s)
Productos Biológicos/análisis , Cianobacterias/química , Descubrimiento de Drogas , Ácidos Grasos/análisis , Cianobacterias/genética , Cianobacterias/metabolismo , Marcaje Isotópico , Familia de Multigenes , Oxidación-Reducción
11.
J Chem Inf Model ; 60(8): 3969-3984, 2020 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-32692555

RESUMEN

G-Protein coupled receptors (GPCRs) are involved in a myriad of pathways key for human physiology through the formation of complexes with intracellular partners such as G-proteins and arrestins (Arrs). However, the structural and dynamical determinants of these complexes are still largely unknown. Herein, we developed a computational big-data pipeline that enables the structural characterization of GPCR complexes with no available structure. This pipeline was used to study a well-known group of catecholamine receptors, the human dopamine receptor (DXR) family and its complexes, producing novel insights into the physiological properties of these important drug targets. A detailed description of the protein interfaces of all members of the DXR family (D1R, D2R, D3R, D4R, and D5R) and the corresponding protein interfaces of their binding partners (Arrs: Arr2 and Arr3; G-proteins: Gi1, Gi2, Gi3, Go, Gob, Gq, Gslo, Gssh, Gt2, and Gz) was generated. To produce reliable structures of the DXR family in complex with either G-proteins or Arrs, we performed homology modeling using as templates the structures of the ß2-adrenergic receptor (ß2AR) bound to Gs, the rhodopsin bound to Gi, and the recently acquired neurotensin receptor-1 (NTSR1) and muscarinic 2 receptor (M2R) bound to arrestin (Arr). Among others, the work demonstrated that the three partner groups, Arrs and Gs- and Gi-proteins, are all structurally and dynamically distinct. Additionally, it was revealed the involvement of different structural motifs in G-protein selective coupling between D1- and D2-like receptors. Having constructed and analyzed 50 models involving DXR, this work represents an unprecedented large-scale analysis of GPCR-intracellular partner interface determinants. All data is available at www.moreiralab.com/resources/dxr.


Asunto(s)
Arrestinas , Proteínas de Unión al GTP , Receptores Acoplados a Proteínas G/metabolismo , Humanos , Receptores Adrenérgicos beta 2/metabolismo , Receptores Dopaminérgicos , Transducción de Señal
12.
Chem Res Toxicol ; 32(4): 566-577, 2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-30868869

RESUMEN

We present an in silico approach for modeling the noncovalent interactions between the human mitochondrial voltage-dependent anion channel (hVDAC1) and a family of single-walled carbon nanotubes (SWCNTs) with a defined pattern of topological vacancies ( v = 1-16), obtained by removing atoms from the SWCNT surface. The general results showed more stable docking interaction complexes (SWCNT-hVDAC1), with more negative Gibbs free energy of binding affinity values, and a strong dependence on the vacancy number ( R2 = 0.93) and vacancy formation energy ( R2 = 0.96). In addition, for most of the SWCNT vacancies that were analyzed, the interatomic distances for the interactions of the SWCNT-hVDAC1 complex with the functional catalytic residues (i.e., Pro7, Gln199, Gln182, Phe181, Val20, Asp19, Lys15, Gly14, Asp12, Ala11, and Arg18) that form the hVDAC1 active site (i.e., the voltage-sensing N-terminal α-helix segment) were very similar to or shorter than the interatomic distances of these residues for ATP-hVDAC1 interactions. In particular, the hVDAC1 residues that can be phosphorylated like Tyr10, Tyr198, and Se16 were significantly perturbed by the interactions with SWCNT with at least nine vacancies. In addition, the SWCNT vacancy family members can affect the flexibility properties of the hVDAC1 N-terminal α-helix segment inducing different patterns of local perturbations in inter-residue communication. Finally, vacancy quantitative structure-binding relationships (V-QSBRs) were unveiled for setting up a robust model that can predict the strength of docking interactions between SWCNTs with a specific topological vacancy and hVDAC1. The developed V-QSBR model classified properly all of the SWCNTs with a different number of SWCNT vacancies with exceptional sensitivity and specificity (both equal to 100%), indicating a strong potential to unequivocally predict the influence of SWCNT vacancies on the mitochondrial channel interactions.


Asunto(s)
Mitocondrias/química , Simulación del Acoplamiento Molecular , Nanotubos de Carbono/química , Canal Aniónico 1 Dependiente del Voltaje/química , Humanos , Relación Estructura-Actividad
13.
Inorg Chem ; 56(4): 2124-2134, 2017 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-28134513

RESUMEN

In order to better understand the epoxide-formation step of the Sharpless epoxidation process, a set of 263 oxygen-transfer reactions reflecting the complexity of the Sharpless epoxidation process were studied using density functional theory (DFT) and Bader's quantum theory of atoms in molecules (QTAIM). The diversity within these reactions reflects the different ligands in the coordination sphere of vanadium and also different substrates (alkene and an allylic alcohol both free and in the form of an alcoxo ligand). The transition states for 76 of these reactions were also characterized using DFT and QTAIM, allowing for an estimation of the impact of the different ligands and substrates on the activation barriers. A smaller subset of the latter was further subjected to an ab initio molecular dynamics (AIMD) simulation coupled to QTAIM analysis. The results show that the type of active catalyst plays an important role in the thermodinamic outcome of these reactions, with vanadium(V) tert-butylhydroperoxide adducts being responsible for the most exoenergetic reactions. On the other hand, the different ligands tested play only a limited role in modulating the thermodynamics and kinetics of these reactions. Moreover, no evidence was found to support a thermodynamic or kinetic preference for the epoxidation of an allylic alcohol over that of an unfunctionalized alkene. However, the results suggest that the reaction path is strongly influenced by the orientation of the substrate upon approximation to the active catalyst, confirming the well-known regioselectivity of the Sharpless epoxidation process.

14.
Phys Chem Chem Phys ; 19(25): 16693-16701, 2017 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-28621368

RESUMEN

This work presents a comprehensive evaluation of the phase behaviour and cohesive enthalpy of protic ionic liquids (PILs) composed of 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) organic superbases with short-chain length (acetic, propionic and butyric) carboxylic acids. Glass transition temperatures, Tg, and enthalpies of vaporization, ΔHvap, were measured for six [BH][A] (1 : 1) PILs (B = DBN, DBU; A = MeCOO, EtCOO, nPrCOO), revealing more significant changes upon increasing the number of -CH2- groups in the base than in the acid. The magnitude of ΔHvap evidences that liquid PILs have a high proportion of ions, although the results also indicate that in DBN PILs the concentration of neutral species is not negligible. In the gas phase, these PILs exist as a distribution of ion pairs and isolated neutral species, with speciation being dependent on the temperature and pressure conditions - at high temperatures and low pressures the separated neutral species dominate. The higher Tg and ΔHvap of the DBU PILs are explained by the stronger basicity of DBU (as supported by NMR and computational calculations), which increases the extent of proton exchange and the ionic character of the corresponding PILs, resulting in stronger intermolecular interactions in condensed phases.

15.
Crit Rev Biotechnol ; 36(2): 317-26, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25264571

RESUMEN

Since the first report by Ishiwata in 1902 of a Bombyx mori infection, followed by the description by Berliner, Bacillus thuringiensis (Bt) has become the main microorganism used in biological control. The application of Bt to combat invertebrates of human interest gained momentum with the growing demand for food free of chemical pesticides and with the implementation of agriculture methods that were less damaging to the environment. However, the mechanisms of action of these products have not been fully elucidated. There are two proposed models: the first is that Bt causes an osmotic imbalance in response to the formation of pores in a cell membrane, and the second is that it causes an opening of ion channels that activate the process of cell death. There are various ways in which Bt resistance can develop: changes in the receptors that do not recognize the Cry toxin, the synthesis of membrane transporters that eliminate the peptides from the cytosol and the development of regulatory mechanisms that disrupt the production of toxin receptors. Besides the potential for formulation of biopesticides and the use in developing genetically modified cultivars, recent studies with Bt have discussed promising applications in other branches of science. Chitinase, an enzyme that degrades chitin, increases the efficiency of Bt insecticides, and there has been of increasing interest in the industry, given that its substrate is extremely abundant in nature. Another promising field is the potential for Bt proteins to act against cancer cells. Parasporins, toxins of Bt that do not have an entomopathogenic effect, have a cytotoxic effect on the cells changed by some cancers. This demonstrates the potential of the microorganism and new opportunities opening for future applications.


Asunto(s)
Bacillus thuringiensis , Control Biológico de Vectores , Bacillus thuringiensis/química , Bacillus thuringiensis/metabolismo , Bacillus thuringiensis/fisiología , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas , Quitinasas , Endotoxinas , Proteínas Hemolisinas , Porosidad
16.
Inorg Chem ; 55(7): 3653-62, 2016 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-26974465

RESUMEN

The possibility of linkage isomerism in a number of vanadium(IV) and vanadium(V) complexes with acetate was surveyed using Density Functional Theory (DFT) and Bader's Quantum Theory of Atoms in Molecules (QTAIM). The results show that vanadium-acetate linkages may be classified as bidentate symmetrical, bidentate asymmetrical, or monodentate, the latter being observed in about 40% of the cases. These latter ones correspond to situations where the two oxygen atoms of the acetate moiety are not equivalent. They are associated with an energy penalty of about 263 kJ·mol(-1), as determined by the distribution of the scaled kinetic energy of the atomic basins forming the acetate ligand. In the presence of bidentate symmetrical vanadium-acetate linkages, the inner valence-shell charge concentrations on the vanadium atom deviate from the traditional VSEPR-derived arrangement, with an energy penalty of about 780 kJ·mol(-1). A compromise situation is partially accomplished in the case of bidentate asymmetrical linkages, which allow a Gillespiean-like arrangement of the inner valence-shell charge concentrations. In this case, one of these local charge concentrations lies close to a V-OAcO bond, which slightly disrupts the equivalence between the two oxygen atoms in the acetate ligand.

17.
Phys Chem Chem Phys ; 18(24): 16555-65, 2016 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-27273193

RESUMEN

Tris(8-hydroxyquinolinate) metallic complexes, Mq3, are one of the most important classes of organic semiconductor materials. Herein, the nature of the chemical bond in Mq3 complexes and its implications on their molecular properties were investigated by a combined experimental and computational approach. Various Mq3 complexes, resulting from the alteration of the metal and substitution of the 8-hydroxyquinoline ligand in different positions, were prepared. The mer-/fac-isomerism in Mq3 was explored by FTIR and NMR spectroscopy, evidencing that, irrespective of the substituent, mer- and fac-are the most stable molecular configurations of Al(iii) and In(iii) complexes, respectively. The relative M-ligand bond dissociation energies were evaluated experimentally by electrospray ionization tandem mass spectrometry (ESI-MS-MS), showing a non-monotonous variation along the group (Al > In > Ga). The results reveal a strong covalent character in M-ligand bonding, which allows for through-ligand electron delocalization, and explain the preferred molecular structures of Mq3 complexes as resulting from the interplay between bonding and steric factors. The mer-isomer reduces intraligand repulsions, being preferred for smaller metals, while the fac-isomer is favoured for larger metals where stronger covalent M-ligand bonds can be formed due to more extensive through-ligand conjugation mediated by metal "d" orbitals.

18.
Int J Mol Sci ; 17(8)2016 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-27472327

RESUMEN

Understanding protein-protein interactions is a key challenge in biochemistry. In this work, we describe a more accurate methodology to predict Hot-Spots (HS) in protein-protein interfaces from their native complex structure compared to previous published Machine Learning (ML) techniques. Our model is trained on a large number of complexes and on a significantly larger number of different structural- and evolutionary sequence-based features. In particular, we added interface size, type of interaction between residues at the interface of the complex, number of different types of residues at the interface and the Position-Specific Scoring Matrix (PSSM), for a total of 79 features. We used twenty-seven algorithms from a simple linear-based function to support-vector machine models with different cost functions. The best model was achieved by the use of the conditional inference random forest (c-forest) algorithm with a dataset pre-processed by the normalization of features and with up-sampling of the minor class. The method has an overall accuracy of 0.80, an F1-score of 0.73, a sensitivity of 0.76 and a specificity of 0.82 for the independent test set.


Asunto(s)
Biología Computacional/métodos , Aprendizaje Automático , Mapeo de Interacción de Proteínas/métodos , Proteínas/química , Proteínas/metabolismo , Algoritmos , Bases de Datos de Proteínas , Humanos , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas
19.
J Chem Inf Model ; 55(5): 1077-86, 2015 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-25845030

RESUMEN

Due to the importance of hot-spots (HS) detection and the efficiency of computational methodologies, several HS detecting approaches have been developed. The current paper presents new models to predict HS for protein-protein and protein-nucleic acid interactions with better statistics compared with the ones currently reported in literature. These models are based on solvent accessible surface area (SASA) and genetic conservation features subjected to simple Bayes networks (protein-protein systems) and a more complex multi-objective genetic algorithm-support vector machine algorithms (protein-nucleic acid systems). The best models for these interactions have been implemented in two free Web tools.


Asunto(s)
Biología Computacional/métodos , ADN/metabolismo , Proteínas/metabolismo , ARN/metabolismo , Solventes/química , Algoritmos , ADN/química , Internet , Modelos Moleculares , Conformación de Ácido Nucleico , Unión Proteica , Conformación Proteica , Proteínas/química , ARN/química , Máquina de Vectores de Soporte , Propiedades de Superficie
20.
Phys Chem Chem Phys ; 17(37): 23917-23, 2015 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-26309143

RESUMEN

The host-guest chemistry of ferrocene derivatives was explored by a combined experimental and theoretical study. Several 1-arylferrocenes and 1,1'-diarylferrocenes were synthesized by the Suzuki-Miyaura cross-coupling reaction. The ability of these compounds to bind small cations in the gas phase was investigated experimentally by electrospray ionization mass spectrometry (ESI-MS). The results evidenced a noticeable ability of all 1,1'-diarylferrocenes studied to bind cations, while the same was not observed for the corresponding 1-arylferrocenes nor ferrocene. The 1,1'-diarylferrocenecation relative interaction energies were evaluated by ESI-MS and quantum chemical calculations and showed that cation binding in these systems follows electrostatic trends. It was found that, due to their unique molecular shape and smooth torsional potentials, 1,1'-diarylferrocenes can act as molecular tweezers of small-sized cations in the gas phase.

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