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1.
Braz J Biol ; 84: e275155, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38808781

RESUMEN

Infections caused by Candida spp. are frequent in critically hospitalized patients, especially among premature neonates, representing one of the most common healthcare-related infections. Although there is considerable production of current knowledge about the mechanisms of immune response, aspects involved in the newborn's innate defense are not fully understood. The aim of this study was to describe the innate immune mechanisms involved in the defense of neonates against invasive candidiasis. This is an integrative literature review from the Scopus, Scifinder, Medline, Web of Science databases and the electronic libraries ScienceDirect and Scielo, in the period between 2002 and 2020, with rescue based on primary descriptor Immunity Innate plus secondary descriptors Candidiasis Invasive AND Infant Newborn. We have observed the involvement of various mechanisms in the neonatal response against invasive candidiasis, including the recognition, signaling, recruitment, and initiation of an effective immune response. These mechanisms encompass the presence of antimicrobial peptides, phagocytosis, synthesis of reactive oxygen species, inflammatory mediators, and complex cell signaling systems mediated by Pattern Recognition Receptors (PRRs). With this study, it is expected to contribute to the expansion of knowledge about the immunological mechanisms involved in the innate immune response of the newborn against disseminated infections caused by Candida species, and in the same sense, highlight the importance of this knowledge as a reflex in the decrease in mortality in the neonatal period.


Asunto(s)
Candidiasis Invasiva , Inmunidad Innata , Inmunidad Innata/inmunología , Humanos , Candidiasis Invasiva/inmunología , Recién Nacido
2.
Phys Rev Lett ; 130(8): 089901, 2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36898127

RESUMEN

This corrects the article DOI: 10.1103/PhysRevLett.129.180402.

3.
Sci Rep ; 12(1): 15502, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109598

RESUMEN

Gulosibacter molinativorax ON4T is the only known organism to produce molinate hydrolase (MolA), which catalyses the breakdown of the thiocarbamate herbicide into azepane-1-carboxylic acid (ACA) and ethanethiol. A combined genomic and transcriptomic strategy was used to fully characterize the strain ON4T genome, particularly the molA genetic environment, to identify the potential genes encoding ACA degradation enzymes. Genomic data revealed that molA is the only catabolic gene of a novel composite transposon (Tn6311), located in a novel low copy number plasmid (pARLON1) harbouring a putative T4SS of the class FATA. pARLON1 had an ANI value of 88.2% with contig 18 from Agrococcus casei LMG 22410T draft genome. Such results suggest that pARLON1 is related to genomic elements of other Actinobacteria, although Tn6311 was observed only in strain ON4T. Furthermore, genomic and transcriptomic data demonstrated that the genes involved in ACA degradation are chromosomal. Based on their overexpression when growing in the presence of molinate, the enzymes potentially involved in the heterocyclic ring breakdown were predicted. Among these, the activity of a protein related to caprolactone hydrolase was demonstrated using heterologous expression. However, further studies are needed to confirm the role of the other putative enzymes.


Asunto(s)
Actinomycetales , Herbicidas , Actinobacteria , Actinomycetales/genética , Azepinas , Herbicidas/metabolismo , Hidrolasas/genética , Hidrolasas/metabolismo , Tiocarbamatos
4.
Dalton Trans ; 51(34): 13032-13045, 2022 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-35968924

RESUMEN

The use of purely organic materials is a promising approach for the miniaturization of devices due to their interesting optical, electronic and magnetic properties. Bisdithiazolyl-based bisDTA compounds have emerged as promising candidates for radical-based single component conductors exhibiting simultaneously magnetic properties. Our computational work focuses on the intriguing magnetism of 4 isostructural pyridine-bridged bisDTA-multifunctional materials triggered by their magnetic and conducting properties being strongly dependent on the different S/Se ratios in the neutral radical skeleton: specifically, bisdithiazolyl (S,S) displays no magnetic order at low temperatures, thiaselenazolyl (Se,S) exhibits spin-canted antiferromagnetism (AFM), and both (S,Se) and bisdiselenazolyl (Se,Se) behave as bulk ferromagnets (FM). Our results reveal that (1) the magnetic response depends on the existence of an intricate network of both AFM and FM spin exchange JAB couplings between neighbouring radicals; and (2) the structural arrangement of π-stacked pairs of radicals sits on a point in the configurational space that is very close to a crossover region where JAB switches from AFM to FM. Indeed, for bulk FM, the experimental response is only accounted for when considering an ab initio optimised crystal structure able to portray adequately the electronic structure of bisDTAs in the region close to the temperature at which magnetic ordering emerges. Magneto-structural correlation maps show the large sensitivity of JAB to very small structural changes with temperature along the π-stacks that lead to drastic changes in the magnetic properties. Clearly, the understanding of magnetism in the title bisDTA compounds is decisive to rationally tailor the properties of multifunctional materials by subtle structural modifications of their crystal packing.

5.
Adv Protein Chem Struct Biol ; 131: 45-83, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35871896

RESUMEN

Cells suffer from perturbations by different stimuli, which, consequently, rise to individual alterations in their profile and function that may end up affecting the tissue as a whole. This is no different if we consider the effect of a therapeutic agent on a biological system. As cells are exposed to external ligands their profile can change at different single-omics levels. Detecting how these changes take place through different sequencing technologies is key to a better understanding of the effects of therapeutic agents. Single-cell RNA-sequencing stands out as one of the most common approaches for cell profiling and perturbation analysis. As a result, single-cell transcriptomics data can be integrated with other omics data sources, such as proteomics and epigenomics data, to clarify the perturbation effects and mechanism at the cell level. Appropriate computational tools are key to process and integrate the available information. This chapter focuses on the recent advances on ligand-induced perturbation and single-cell omics computational tools and algorithms, their current limitations, and how the deluge of data can be used to improve the current process of drug research and development.


Asunto(s)
Genómica , Metabolómica , Epigenómica , Ligandos , Fenotipo
6.
Mol Psychiatry ; 27(5): 2457-2469, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35256745

RESUMEN

Mutations linked to neurodevelopmental disorders, such as intellectual disability (ID), are frequently found in genes that encode for proteins of the excitatory synapse. Transmembrane AMPA receptor regulatory proteins (TARPs) are AMPA receptor auxiliary proteins that regulate crucial aspects of receptor function. Here, we investigate a mutant form of the TARP family member stargazin, described in an ID patient. Molecular dynamics analyses predicted that the ID-associated stargazin variant, V143L, weakens the overall interface of the AMPAR:stargazin complex and impairs the stability of the complex. Knock-in mice harboring the V143L stargazin mutation manifest cognitive and social deficits and hippocampal synaptic transmission defects, resembling phenotypes displayed by ID patients. In the hippocampus of stargazin V143L mice, CA1 neurons show impaired spine maturation, abnormal synaptic transmission and long-term potentiation specifically in basal dendrites, and synaptic ultrastructural alterations. These data suggest a causal role for mutated stargazin in the pathogenesis of ID and unveil a new role for stargazin in the development and function of hippocampal synapses.


Asunto(s)
Canales de Calcio , Discapacidad Intelectual , Receptores AMPA , Animales , Canales de Calcio/genética , Canales de Calcio/metabolismo , Hipocampo/metabolismo , Humanos , Discapacidad Intelectual/genética , Discapacidad Intelectual/metabolismo , Ratones , Mutación/genética , Receptores AMPA/genética , Receptores AMPA/metabolismo , Sinapsis/metabolismo , Transmisión Sináptica/genética
7.
Parkinsons Dis ; 2021: 5553460, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34221341

RESUMEN

INTRODUCTION: Pain is a major nonmotor symptom of Parkinson's disease (PD), and central parkinsonian pain is the core feature of the putative Park pain subtype of PD. This study aimed to explore the cognitive and behavioral profile of PD patients with central parkinsonian pain. Material and Methods. A structured interview was used to identify and characterize pain in a cohort of 260 consecutive PD patients. The Ford classification of pain was applied. The Dementia Rating Scale-2 (DRS-2) and the Impulse Control Disorders in Parkinson's Disease Short Form (QUIP-S) were administered, and patients' smoking habits were recorded. The Unified Parkinson's Disease Rating Scale (UPDRS) was used to assess motor and nonmotor symptoms in off and on conditions. RESULTS: One hundred and eighty-eight patients (68%) reported pain; and in 41 (22%) of them, the pain was classified as central parkinsonian pain. PD patients with central parkinsonian pain had better cognitive performance in DRS-2 Initiation/Perseveration and Conceptualization subscales but reported more other compulsive behaviors (e.g., hobbyism, punding, and walkabout) and had more current smoking habits than those without pain or with non-central parkinsonian pain. Multiple logistic regression analyses revealed that the DRS-2 Conceptualization subscale, other compulsive behaviors, and smoking habits remained statistically associated with central parkinsonian pain even when other significant covariates were considered. Only patients with pain, regardless of type, had a gambling disorder. Discussion. The study results provide further evidence that pain revealed that patients with central parkinsonian pain are more likely to present compulsive or addictive behaviors, despite having more preserved cognitive performance. Patients with central parkinsonian pain appear to have a distinct phenotype of PD.

9.
Mult Scler Relat Disord ; 46: 102486, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32916510

RESUMEN

BACKGROUND: Olfactory dysfunction has been linked to clinical severity variables in multiple MS populations. Though, its prognostic value is still unknown. OBJECTIVE: The aim of this study was to explore the long-term outcome associated with Brief-Smell Identification Test (B-SIT) performance in a cohort of MS patients. METHODS: A retrospective review of the clinical records was conducted in 149 patients who participated in a previous study, with a median follow-up of 121 months. Demographic and clinical data regarding the last clinical appointment with EDSS measurement were collected. Multiple Sclerosis Severity Scale (MSSS) and Age-Related Multiple Sclerosis Severity (ARMSS) scores were calculated. Date of the last clinical contact or death was recorded. RESULTS: Among MS patients with progressive clinical course (n = 33), those with impaired B-SIT at baseline had greater change per month during follow-up (as measured by increases in MSSS and ARMSS scores) and a higher hazard of death. No significant associations were found among patients with relapsing and remitting MS (n = 116). CONCLUSIONS: The study results demonstrate that odor identification impairment has prognostic value in progressive MS, suggesting that a brief odor identification measure can be a marker of neurodegeneration in progressive MS.


Asunto(s)
Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Estudios de Seguimiento , Humanos , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/diagnóstico , Odorantes , Pronóstico , Estudios Retrospectivos
10.
Sci Total Environ ; 701: 134755, 2020 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-31704398

RESUMEN

The objective of this study is to analyze the short-term effects of atmospheric pollutant concentrations (PM10, NO2 and O3) and heat and cold waves on the number of pre-term births and cases of low birth weight related to Saharan dust advection and biomass combustion. The dependent variables used in this analysis were the total number of births, births with low weight (>2.500 g) and pre-term births (<37 weeks), that occurred at the province level. Data provided by the NSI included: days with Saharan dust intrusion or biomass advection classified in terms of information provided by MITECO for each of the nine regions in Spain. A representative city was selected for reach region in which the registered average daily concentrations of PM10, NO2 and O3 (µg/m3) were used. These were also provided by MITECO. The daily maximum and daily minimum temperature (°C) used was those registered by the meteorological observatory station located in each province capital, provided by AEMET. Using Poisson log linear regression models, the associated relative risks (RR) were measured as well as the population attributable risk (PAR) corresponding to the variables that resulted statistically significant at p < 0.05 for days with and without intrusion of natural particulate matter. The results obtained show that the days with Saharan dust intrusion or advections due to biomass combustion- beyond the impact of PM10, primary pollutants such as NO2 (in Saharan intrusions), heat waves and O3 - are associated with the number of births, low birth weight and pre-term birth. The RR and percent PAR of the pollutants and the heat waves are greater than those obtained for PM10. The results of this study indicate that days with natural particulate matter due to biomass combustion or advection of Saharan dust put pregnant women at risk.


Asunto(s)
Contaminación del Aire/estadística & datos numéricos , Polvo/análisis , Exposición Materna/estadística & datos numéricos , Resultado del Embarazo/epidemiología , África del Norte , Monitoreo del Ambiente , Femenino , Humanos , Material Particulado/análisis , Embarazo , España
11.
J Pain Res ; 12: 2137-2144, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31372031

RESUMEN

INTRODUCTION: Sleep disturbances and pain are common non-motor symptoms in Parkinson's disease (PD). This study aimed to explore the association between these two symptoms in a cohort of patients with PD. MATERIALS AND METHODS: The Parkinson's Disease Sleep Scale (PDSS-2) was used to identify sleep disturbances in a series of 229 PD patients. The identification and characterization of pain was performed by a semi-structured interview and by the application of the Ford classification and the Brief Pain Inventory (BPI). The Unified Parkinson's Disease Rating Scale-III, Hoehn & Yahr (H&Y), and Schwab and England Independence Scale were used to assess motor symptoms and functional independence in off and on conditions. The Hospital Anxiety and Depression Scale (HADS) and SF-36 were applied to screen for anxiety and depression and to evaluate the quality of life. Non-parametric tests were used for group comparisons and logistic regressions were applied to explore predictors of sleep disturbances. RESULTS: Seventy-five (33%) patients had clinically relevant sleep disturbances (PDSS-2≥18) and 162 patients (71%) reported pain. Of those with pain, 38 (24%) had central parkinsonian pain. PD patients with sleep disturbances experienced more pain and had more severe motor symptoms, lower functional independence, more anxiety and depression symptoms, and worst quality of life. Among patients with pain, central parkinsonian pain was the subtype of pain with the highest odds of sleep disturbances, even when taking into account motor symptoms (H&Y off), motor fluctuations, intensity of pain (BPI), and symptoms of anxiety and depression (HADS). CONCLUSIONS: The association between pain and sleep disturbances in PD appears to be dependent on subtype of pain. The close relationship between central parkinsonian pain and sleep disturbances in PD raises the possibility of common pathophysiological mechanisms. A better understanding of the relationship between sleep disturbances and central parkinsonian pain may contribute to the development of new care strategies in PD patients.

12.
Org Biomol Chem ; 15(31): 6541-6547, 2017 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-28745772

RESUMEN

There is significant interest in the use of unmodified self-assembling peptides as building blocks for functional, supramolecular biomaterials. Recently, dynamic peptide libraries (DPLs) have been proposed to select self-assembling materials from dynamically exchanging mixtures of dipeptide inputs in the presence of a nonspecific protease enzyme, where peptide sequences are selected and amplified based on their self-assembling tendencies. It was shown that the results of the DPL of mixed sequences (e.g. starting from a mixture of dileucine, L2, and diphenylalanine, F2) did not give the same outcome as the separate L2 and F2 libraries (which give rise to the formation of F6 and L6), implying that interactions between these sequences could disrupt the self-assembly. In this study, coarse grained molecular dynamics (CG-MD) simulations are used to understand the DPL results for F2, L2 and mixed libraries. CG-MD simulations demonstrate that interactions between precursors can cause the low formation yield of hexapeptides in the mixtures of dipeptides and show that this ability to disrupt is influenced by the concentration of the different species in the DPL. The disrupting self-assembly effect between the species in the DPL is an important effect to take into account in dynamic combinatorial chemistry as it affects the possible discovery of new materials. This work shows that combined computational and experimental screening can be used complementarily and in combination providing a powerful means to discover new supramolecular peptide nanostructures.


Asunto(s)
Nanoestructuras/química , Biblioteca de Péptidos , Péptidos/química , Simulación de Dinámica Molecular
14.
J Environ Manage ; 182: 486-495, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27526086

RESUMEN

Pharmaceutical persistent pollutants pose a serious threat to the environment. The aim of this study was to use, for the first time, hydroxyapatite-based biomaterials as photocatalysts to degrade micropollutants. Diclofenac and fluoxetine were selected for these initial tests. Hydroxyapatite (Ca10(PO4)(OH)2, HAp) is one of the most commonly used biomaterials/bioceramics, being a major constituent of bone. In this work sustainable HAp-based materials of marine origin, obtained from cod fish bones, were used; these photocatalysts were previously fully studied and characterised. Both single-phase HAp and HAp-titania multicomponent materials (1 wt% TiO2) were employed as UV light photocatalysts, the latter showing better performance, indicated by higher degradation rates of both compounds. The HAp-titania photocatalyst showed excellent degradation of both persistent pollutants, the maximum degradation performance being 100% for fluoxetine and 92% for diclofenac, with pollutant and photocatalyst concentrations of 2 ppm and 4 g/L, respectively. Variations in features such as pollutant and photocatalyst concentrations were investigated, and results showed that generally fluoxetine was degraded more easily than diclofenac. The photocatalyst's crystallinity was not affected by the photodegradation reaction; indeed the material exhibited good photostability, as the degradation rate did not decrease when the material was reused. Tests were also performed using actual treated wastewater; the photocatalyst was still effective, even if with lower efficiency (-20% and -4% for diclofenac and fluoxetine, respectively). TOC analysis showed high but incomplete mineralisation of the pollutants (maximum 60% and 80% for DCF and FXT, respectively).


Asunto(s)
Materiales Biocompatibles/química , Diclofenaco/química , Durapatita/química , Fotólisis , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Acetonitrilos/química , Catálisis , Cristalización , Monitoreo del Ambiente/métodos , Restauración y Remediación Ambiental , Fluoxetina/química , Oxígeno/química , Preparaciones Farmacéuticas/análisis , Polvos , Titanio/química , Rayos Ultravioleta , Purificación del Agua/métodos
15.
Nano Lett ; 16(3): 2066-71, 2016 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-26862681

RESUMEN

The magnetic properties of a nanoscale system are inextricably linked to its local environment. In adatoms on surfaces and inorganic layered structures, the exchange interactions result from the relative lattice positions, layer thicknesses, and other environmental parameters. Here, we report on a sample-dependent sign inversion of the magnetic exchange coupling between the three unpaired spins of an organic triradical molecule embedded in a three-terminal device. This ferro-to-antiferromagnetic transition is due to structural distortions and results in a high-to-low spin ground-state change in a molecule traditionally considered to be a robust high-spin quartet. Moreover, the flexibility of the molecule yields an in situ electric tunability of the exchange coupling via the gate electrode. These findings open a route to the controlled reversal of the magnetic states in organic molecule-based nanodevices by mechanical means, electrical gating, or chemical tailoring.

16.
J Hum Hypertens ; 29(8): 488-94, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25518896

RESUMEN

Systolic hypertension is associated with cognitive decline in the elderly. Altered blood pressure (BP) variability is a possible mechanism of reduced cognitive performance in elderly hypertensives. We hypothesized that altered beat-to-beat systolic BP variability is associated with reduced global cognitive performance in elderly hypertensive subjects. In exploratory analyses, we also studied the correlation between diverse discrete cognitive domains and indices of systolic BP and heart rate variability. Disproving our initial hypothesis, we have shown that hypertension and low education, but not indices of systolic BP and heart rate variability, were independent predictors of lower global cognitive performance. However, exploratory analyses showed that the systolic BP variability in semi-upright position was an independent predictor of matrix reasoning (B = 0.08 ± .03, P-value = 0.005), whereas heart rate variability in semi-upright position was an independent predictor of the executive function score (B = -6.36 ± 2.55, P-value = 0.02). We conclude that myogenic vascular and sympathetic modulation of systolic BP do not contribute to reduced global cognitive performance in treated hypertensive subjects. Nevertheless, our results suggest that both systolic BP and heart rate variability might be associated with modulation of frontal lobe cognitive domains, such as executive function and matrix reasoning.


Asunto(s)
Presión Sanguínea/fisiología , Cognición/fisiología , Frecuencia Cardíaca/fisiología , Hipertensión/fisiopatología , Hipertensión/psicología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Postura
17.
J Chem Inf Model ; 54(7): 2051-67, 2014 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-24941229

RESUMEN

Crystallographic structures of NGF/p75NTR and proNGF/p75NTR were previously obtained in 2:1 and 2:2 stoichiometries, respectively. However, evidence shows that both stoichiometries can occur for mature neurotrophins and pro-neurotrophins. We used Molecular Dynamics (MD) simulations to examine the energetic and structural characteristics of these two complete systems as well as the uncomplexed forms of NGF and understand how these could translate in a new view of different biological outcomes. Here, we show that one chain at the 2:2 proNGF complex seems to be preferentially lost creating a 2:1 structure able to interact with sortilin. We also demonstrated that the structure of the neurotrophin dimers is not pre-established and suffers large structural modifications upon p75NTR binding. Moreover, our data suggests an elegant explanation for the dual role of NGF in neuronal cell death and survival, where different stoichiometries induce conformational changes that might be the basis for the different biological outcomes observed with the mature and proforms of neurotrophins.


Asunto(s)
Simulación de Dinámica Molecular , Factor de Crecimiento Nervioso/química , Factor de Crecimiento Nervioso/metabolismo , Multimerización de Proteína , Precursores de Proteínas/química , Precursores de Proteínas/metabolismo , Receptor de Factor de Crecimiento Nervioso/metabolismo , Unión Proteica , Estructura Cuaternaria de Proteína , Receptor de Factor de Crecimiento Nervioso/química , Termodinámica
18.
Mini Rev Med Chem ; 14(2): 111-22, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24456272

RESUMEN

Since the discovery of the first penicillin bacterial resistance to ß-lactam antibiotics has spread and evolved promoting new resistances to pathogens. The most common mechanism of resistance is the production of ß-lactamases that have spread thorough nature and evolve to complex phenotypes like CMT type enzymes. New antibiotics have been introduced in clinical practice, and therefore it becomes necessary a concise summary about their molecular targets, specific use and other properties. ß-lactamases are still a major medical concern and they have been extensively studied and described in the scientific literature. Several authors agree that Glu166 should be the general base and Ser70 should perform the nucleophilic attack to the carbon of the carbonyl group of the ß-lactam ring. Nevertheless there still is controversy on their catalytic mechanism. TEMs evolve at incredible pace presenting more complex phenotypes due to their tolerance to mutations. These mutations lead to an increasing need of novel, stronger and more specific and stable antibiotics. The present review summarizes key structural, molecular and functional aspects of ESBL, IRT and CMT TEM ß-lactamases properties and up to date diagrams of the TEM variants with defined phenotype. The activity and structural characteristics of several available TEMs in the NCBI-PDB are presented, as well as the relation of the various mutated residues and their specific properties and some previously proposed catalytic mechanisms.


Asunto(s)
Antibacterianos/farmacología , Resistencia betalactámica/efectos de los fármacos , beta-Lactamasas/química , beta-Lactamasas/metabolismo , beta-Lactamas/farmacología , Antibacterianos/química , Humanos , Modelos Moleculares , Estructura Molecular , Relación Estructura-Actividad , beta-Lactamas/química
19.
Clin Exp Immunol ; 175(2): 227-34, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24116927

RESUMEN

Regulatory T cells [Tregs ; CD4(+) CD25(+) forkhead box protein 3 (FoxP3(+) )] are subsets of T cells involved in the maintenance of peripheral self-tolerance by actively suppressing the activation and expansion of autoreactive T cells. Signalling through the interleukin-2 receptor (IL-2R) contributes to T cell tolerance by controlling three important aspects of regulatory T cell (Treg ) biology. CD25 is the α-chain of the IL-2R that, in concert with the ß-chain and γ-chain, constitutes the complete IL-2R. CD25 contributes only to IL-2 binding affinity but not to the recruitment of signalling molecules. However, its importance in the development of a normal immune response is emphasized by the finding that a truncation mutant of CD25 results in an immunodeficiency in humans characterized by an increased susceptibility to viral, bacterial and fungal infections. In 1997, Sharfe et al. described an infant with severe bacterial, viral and fungal infections. Counts of autologous T lymphocytes were moderately low, T cells displayed a weak proliferative response to mitogens in vitro and the patient displayed no rejection of an allogeneic skin graft. However, unlike children with severe combined immunodeficiency (SCID), besides not having circulating T cells, the patient also developed peripheral lymphocytic proliferation and autoimmune primary biliary cirrhosis. We present the first female Argentine patient with mutation in CD25 associated with chronic and severe inflammatory lung disease (follicular bronchiolitis with lymphocyte hyperplasia), eczema and infections. She has no expression of CD25 on CD4(+) T cells and an extremely low amount of Tregs . The molecular study confirmed homozygous missense mutation in the alpha subunit of the IL-2 receptor (CD25αR) (c. 122 a > c; p. Y41S).


Asunto(s)
Bronquiolitis/diagnóstico , Bronquiolitis/genética , Subunidad alfa del Receptor de Interleucina-2/genética , Linfocitos T Reguladores/inmunología , Enfermedades Autoinmunes/diagnóstico , Enfermedades Autoinmunes/genética , Preescolar , Femenino , Humanos , Tolerancia Inmunológica/genética , Tolerancia Inmunológica/inmunología , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Interleucina-2/metabolismo , Cirrosis Hepática Biliar/diagnóstico , Cirrosis Hepática Biliar/genética , Activación de Linfocitos/inmunología , Unión Proteica , Linfocitos T Reguladores/metabolismo
20.
J Chem Inf Model ; 53(10): 2648-58, 2013 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-23991837

RESUMEN

The TEM family of enzymes has had a crucial impact on the pharmaceutical industry due to their important role in antibiotic resistance. Even with the latest technologies in structural biology and genomics, no 3D structure of a TEM-1/antibiotic complex is known previous to acylation. Therefore, the comprehension of their capability in acylate antibiotics is based on the protein macromolecular structure uncomplexed. In this work, molecular docking, molecular dynamic simulations, and relative free energy calculations were applied in order to get a comprehensive and thorough analysis of TEM-1/ampicillin and TEM-1/amoxicillin complexes. We described the complexes and analyzed the effect of ligand binding on the overall structure. We clearly demonstrate that the key residues involved in the stability of the ligand (hot-spots) vary with the nature of the ligand. Structural effects such as (i) the distances between interfacial residues (Ser70-Oγ and Lys73-Nζ, Lys73-Nζ and Ser130-Oγ, and Ser70-Oγ-Ser130-Oγ), (ii) side chain rotamer variation (Tyr105 and Glu240), and (iii) the presence of conserved waters can be also influenced by ligand binding. This study supports the hypothesis that TEM-1 suffers structural modifications upon ligand binding.


Asunto(s)
Aminoácidos/química , Amoxicilina/química , Ampicilina/química , Antibacterianos/química , Simulación del Acoplamiento Molecular , beta-Lactamasas/química , Sitios de Unión , Bacterias Gramnegativas/química , Bacterias Gramnegativas/enzimología , Ligandos , Simulación de Dinámica Molecular , Unión Proteica , Conformación Proteica , Termodinámica , Agua/química , Resistencia betalactámica , Inhibidores de beta-Lactamasas
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