Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 162.432
Filtrar
1.
Sci Adv ; 10(20): eadm7907, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38758787

RESUMEN

Understanding how the amino acid sequence dictates protein structure and defines its stability is a fundamental problem in molecular biology. It is especially challenging for membrane proteins that reside in the complex environment of a lipid bilayer. Here, we obtain an atomic-level picture of the thermally induced unfolding of a membrane-embedded α-helical protein, human aquaporin 1, using solid-state nuclear magnetic resonance spectroscopy. Our data reveal the hierarchical two-step pathway that begins with unfolding of a structured extracellular loop and proceeds to an intermediate state with a native-like helical packing. In the second step, the transmembrane domain unravels as a single unit, resulting in a heterogeneous misfolded state with high helical content but with nonnative helical packing. Our results show the importance of loops for the kinetic stabilization of the whole membrane protein structure and support the three-stage membrane protein folding model.


Asunto(s)
Proteínas de la Membrana , Desplegamiento Proteico , Humanos , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Acuaporina 1/química , Acuaporina 1/metabolismo , Resonancia Magnética Nuclear Biomolecular , Espectroscopía de Resonancia Magnética/métodos , Modelos Moleculares , Pliegue de Proteína , Cinética , Termodinámica
2.
J Mol Model ; 30(6): 177, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38775913

RESUMEN

CONTEXT: Bismuth complexes with dithiocarbamate ligands have attracted attention because of their biological applications, such as antimicrobial, antileishmanial, and anticancer properties. These complexes have high cytotoxic activity against cancer cells, being more active than the standard drugs cisplatin, doxorubicin, and tamoxifen. In the present study, we investigated the ability of some DFT methods to reproduce the geometries and NMR spectra of the Bi(III) dithiocarbamate complexes, selected based on their proven antitumor activity. Our investigation revealed that the M06-L/def2-TZVP/ECP/CPCM method presented good accuracy in predicting geometries, while the TPSSh/def2-SVP/ECP/CPCM method proved effective in analyzing the 13C NMR spectra of these molecules. In general, all examined methods exhibited comparable performance in predicting 1H NMR signals. METHODS: Calculations were performed with the Gaussian 09 program using the def2-SVP and def2-TZVP basis sets, employing relativistic effective core potential (ECP) for Bi and using the CPCM solvent model. The exchange-correlation functionals BP86, PBE, OLYP, M06-L, B3LYP, B3LYP-D3, M06-2X, TPSSh, CAM-B3LYP, and ωB97XD were used in the study. Geometry optimizations were started from crystallographic structures available at the Cambridge Structural Database. The theoretical results were compared with experimental data using the mean root-mean-square deviation (RMSD), mean absolute deviations (MAD), and linear correlation coefficient (R2).


Asunto(s)
Antineoplásicos , Teoría Funcional de la Densidad , Espectroscopía de Resonancia Magnética , Tiocarbamatos , Antineoplásicos/química , Antineoplásicos/farmacología , Tiocarbamatos/química , Espectroscopía de Resonancia Magnética/métodos , Bismuto/química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Modelos Moleculares , Humanos
3.
Food Res Int ; 187: 114373, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38763649

RESUMEN

Effect of complexation of three medium-chain fatty acids (octanoic, decylic and lauric acid, OA, DA and LA, respectively) on structural characteristics, physicochemical properties and digestion behaviors of cassava starch (CS) was investigated. Current study indicated that LA was more easily to combine with CS (complex index 88.9%), followed by DA (80.9%), which was also consistent with their corresponding complexed lipids content. Following the investigation of morphology, short-range ordered structure, helical structure, crystalline/amorphous region and fractal dimension of the various complexes, all cassava starch-fatty acids complexes (CS-FAs) were characterized with a flaked morphology rather than a round morphology in native starch (control CS). X-ray diffraction demonstrated that all CS-FAs had a V-type crystalline structure, and nuclear magnetic resonance spectroscopy confirmed that the complexes made from different fatty acids displayed similar V6 or V7 type polymorphs. Interestingly, small-angle X-ray scattering analysis revealed that α value became greater following increased carbon chain length of fatty acids, indicating the formation of a more ordered fractal structure in the aggregates. Changes in rheological parameters G' and G'' indicated that starch complexed with fatty acids was more likely to form a gel network, but difference among three CS-FAs complexes was significant, which might be contributed to their corresponding hydrophobicity and hydrophilicity raised from individual fatty acids. Importantly, digestion indicated that CS-LA complexes had the lowest hydrolysis degree, followed by the greatest RS content, indicating the importance of chain length of fatty acids for manipulating the fine structure and functionality of the complexes.


Asunto(s)
Digestión , Ácidos Grasos , Ácidos Láuricos , Manihot , Almidón , Difracción de Rayos X , Manihot/química , Almidón/química , Ácidos Láuricos/química , Ácidos Grasos/química , Ácidos Decanoicos/química , Reología , Caprilatos/química , Espectroscopía de Resonancia Magnética
4.
Carbohydr Polym ; 338: 122167, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38763706

RESUMEN

2-Hydroxypropyl-ß-cyclodextrin (HPBCD) is one of the most important cyclodextrin derivatives, finding extensive applications in the pharmaceutical sector. Beyond its role as an excipient, HPBCD achieved orphan drug status in 2015 for Niemann-Pick type C disease treatment, prompting research into its therapeutic potential for various disorders. However, the acceptance of HPBCD as an active pharmaceutical ingredient may be impeded by its complex nature. Indeed, HPBCD is not a single entity with a well-defined structure, instead, it is a complex mixture of isomers varying in substituent positions and the degree of hydroxypropylation, posing several challenges for unambiguous characterization. Pharmacopoeias' methods only address the average hydroxypropylation extent, lacking a rapid approach to characterize the substituent positions on the CD scaffold. Recognizing that the distribution of substituents significantly influences the complexation ability and overall activity of the derivative, primarily by altering cavity dimensions, we present a straightforward and non-destructive method based on liquid state NMR spectroscopy to analyze the positions of the hydroxypropyl sidechains. This method relies on a single set of routine experiments to establish quantitative assignment and it provides a simple yet effective tool to disclose the substitution pattern of this complex material, utilizing easily accessible (400 MHz NMR) instrumentation.


Asunto(s)
2-Hidroxipropil-beta-Ciclodextrina , Espectroscopía de Resonancia Magnética , 2-Hidroxipropil-beta-Ciclodextrina/química , Espectroscopía de Resonancia Magnética/métodos , Excipientes/química
5.
J Am Heart Assoc ; 13(10): e034364, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38726919

RESUMEN

BACKGROUND: Comprehensive blood lipoprotein profiles and their association with incident coronary heart disease (CHD) among racially and geographically diverse populations remain understudied. METHODS AND RESULTS: We conducted nested case-control studies of CHD among 3438 individuals (1719 pairs), including 1084 White Americans (542 pairs), 1244 Black Americans (622 pairs), and 1110 Chinese adults (555 pairs). We examined 36 plasma lipids, lipoproteins, and apolipoproteins, measured by nuclear magnetic resonance spectroscopy, with incident CHD among all participants and subgroups by demographics, lifestyle, and metabolic health status using conditional or unconditional logistic regression adjusted for potential confounders. Conventionally measured blood lipids, that is, total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol, were each associated with incident CHD, with odds ratios (ORs) being 1.33, 1.32, 1.24, and 0.79 per 1-SD increase among all participants. Seventeen lipoprotein biomarkers showed numerically stronger associations than conventional lipids, with ORs per 1-SD among all participants ranging from 1.35 to 1.57 and a negative OR of 0.78 (all false discovery rate <0.05), including apolipoprotein B100 to apolipoprotein A1 ratio (OR, 1.57 [95% CI, 1.45-1.7]), low-density lipoprotein-triglycerides (OR, 1.55 [95% CI, 1.43-1.69]), and apolipoprotein B (OR, 1.49 [95% CI, 1.37-1.62]). All these associations were significant and consistent across racial groups and other subgroups defined by age, sex, smoking, obesity, and metabolic health status, including individuals with normal levels of conventionally measured lipids. CONCLUSIONS: Our study highlighted several lipoprotein biomarkers, including apolipoprotein B/ apolipoprotein A1 ratio, apolipoprotein B, and low-density lipoprotein-triglycerides, strongly and consistently associated with incident CHD. Our results suggest that comprehensive lipoprotein measures may complement the standard lipid panel to inform CHD risk among diverse populations.


Asunto(s)
Apolipoproteínas , Biomarcadores , Negro o Afroamericano , Enfermedad Coronaria , Lipoproteínas , Población Blanca , Humanos , Masculino , Femenino , Persona de Mediana Edad , Enfermedad Coronaria/sangre , Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/etnología , Enfermedad Coronaria/diagnóstico , Estudios Prospectivos , Estudios de Casos y Controles , Lipoproteínas/sangre , Anciano , Apolipoproteínas/sangre , Biomarcadores/sangre , Lípidos/sangre , Incidencia , Asiático/estadística & datos numéricos , Adulto , Estados Unidos/epidemiología , Factores de Riesgo , Medición de Riesgo , Espectroscopía de Resonancia Magnética , Triglicéridos/sangre
6.
Sci Adv ; 10(19): eade9520, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38718112

RESUMEN

Fast collective motions are widely present in biomolecules, but their functional relevance remains unclear. Herein, we reveal that fast collective motions of backbone are critical to the water transfer of aquaporin Z (AqpZ) by using solid-state nuclear magnetic resonance (ssNMR) spectroscopy and molecular dynamics (MD) simulations. A total of 212 residue site-specific dipolar order parameters and 158 15N spin relaxation rates of the backbone are measured by combining the 13C- and 1H-detected multidimensional ssNMR spectra. Analysis of these experimental data by theoretic models suggests that the small-amplitude (~10°) collective motions of the transmembrane α helices on the nanosecond-to-microsecond timescales are dominant for the dynamics of AqpZ. The MD simulations demonstrate that these collective motions are critical to the water transfer efficiency of AqpZ by facilitating the opening of the channel and accelerating the water-residue hydrogen bonds renewing in the selectivity filter region.


Asunto(s)
Acuaporinas , Simulación de Dinámica Molecular , Agua , Agua/química , Acuaporinas/química , Acuaporinas/metabolismo , Conformación Proteica en Hélice alfa , Enlace de Hidrógeno , Espectroscopía de Resonancia Magnética , Resonancia Magnética Nuclear Biomolecular , Proteínas de Escherichia coli
7.
Molecules ; 29(9)2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38731405

RESUMEN

Chitin, a ubiquitous biopolymer, holds paramount scientific and economic significance. Historically, it has been primarily isolated from marine crustaceans. However, the surge in demand for chitin and the burgeoning interest in biopolymers have necessitated the exploration of alternative sources. Among these methods, the mulberry silkworm (Bombyx mori) has emerged as a particularly intriguing prospect. To isolate chitin from Bombyx mori, a chemical extraction methodology was employed. This process involved a series of meticulously orchestrated steps, including Folch extraction, demineralization, deproteinization, and decolorization. The resultant chitin was subjected to comprehensive analysis utilizing techniques such as attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), 13C nuclear magnetic resonance (NMR) spectroscopy, and wide-angle X-ray scattering (WAXS). The obtained results allow us to conclude that the Bombyx mori represents an attractive alternative source of α-chitin.


Asunto(s)
Bombyx , Quitina , Bombyx/química , Animales , Quitina/química , Quitina/aislamiento & purificación , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Espectroscopía de Resonancia Magnética , Morus/química
8.
Molecules ; 29(9)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38731577

RESUMEN

Recently, benchtop nuclear magnetic resonance (NMR) spectrometers utilizing permanent magnets have emerged as versatile tools with applications across various fields, including food and pharmaceuticals. Their efficacy is further enhanced when coupled with chemometric methods. This study presents an innovative approach to leveraging a compact benchtop NMR spectrometer coupled with chemometrics for screening honey-based food supplements adulterated with active pharmaceutical ingredients. Initially, fifty samples seized by French customs were analyzed using a 60 MHz benchtop spectrometer. The investigation unveiled the presence of tadalafil in 37 samples, sildenafil in 5 samples, and a combination of flibanserin with tadalafil in 1 sample. After conducting comprehensive qualitative and quantitative characterization of the samples, we propose a chemometric workflow to provide an efficient screening of honey samples using the NMR dataset. This pipeline, utilizing partial least squares discriminant analysis (PLS-DA) models, enables the classification of samples as either adulterated or non-adulterated, as well as the identification of the presence of tadalafil or sildenafil. Additionally, PLS regression models are employed to predict the quantitative content of these adulterants. Through blind analysis, this workflow allows for the detection and quantification of adulterants in these honey supplements.


Asunto(s)
Suplementos Dietéticos , Miel , Espectroscopía de Resonancia Magnética , Miel/análisis , Suplementos Dietéticos/análisis , Espectroscopía de Resonancia Magnética/métodos , Citrato de Sildenafil/análisis , Flujo de Trabajo , Quimiometría/métodos , Tadalafilo/análisis , Análisis de los Mínimos Cuadrados , Contaminación de Medicamentos/prevención & control , Análisis Discriminante
9.
Sci Rep ; 14(1): 10781, 2024 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-38734781

RESUMEN

Magnetic resonance (MR) acquisitions of the torso are frequently affected by respiratory motion with detrimental effects on signal quality. The motion of organs inside the body is typically decoupled from surface motion and is best captured using rapid MR imaging (MRI). We propose a pipeline for prospective motion correction of the target organ using MR image navigators providing absolute motion estimates in millimeters. Our method is designed to feature multi-nuclear interleaving for non-proton MR acquisitions and to tolerate local transmit coils with inhomogeneous field and sensitivity distributions. OpenCV object tracking was introduced for rapid estimation of in-plane displacements in 2D MR images. A full three-dimensional translation vector was derived by combining displacements from slices of multiple and arbitrary orientations. The pipeline was implemented on 3 T and 7 T MR scanners and tested in phantoms and volunteers. Fast motion handling was achieved with low-resolution 2D MR image navigators and direct implementation of OpenCV into the MR scanner's reconstruction pipeline. Motion-phantom measurements demonstrate high tracking precision and accuracy with minor processing latency. The feasibility of the pipeline for reliable in-vivo motion extraction was shown on heart and kidney data. Organ motion was manually assessed by independent operators to quantify tracking performance. Object tracking performed convincingly on 7774 navigator images from phantom scans and different organs in volunteers. In particular the kernelized correlation filter (KCF) achieved similar accuracy (74%) as scored from inter-operator comparison (82%) while processing at a rate of over 100 frames per second. We conclude that fast 2D MR navigator images and computer vision object tracking can be used for accurate and rapid prospective motion correction. This and the modular structure of the pipeline allows for the proposed method to be used in imaging of moving organs and in challenging applications like cardiac magnetic resonance spectroscopy (MRS) or magnetic resonance imaging (MRI) guided radiotherapy.


Asunto(s)
Fantasmas de Imagen , Humanos , Espectroscopía de Resonancia Magnética/métodos , Imagen por Resonancia Magnética/métodos , Respiración , Procesamiento de Imagen Asistido por Computador/métodos , Movimiento (Física) , Movimiento , Algoritmos
10.
Nat Prod Res ; 38(11): 1864-1873, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38739563

RESUMEN

Phytochemical studies of the stems and leaves of Stephania dielsiana Y.C.Wu yielded two new aporphine alkaloids (1 and 5), along with six known alkaloids (2-4 and 6-8). Their structures were characterised based on analyses of spectroscopic data, including one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS). The cytotoxic activities of the isolated compounds against a small panel of tumour cell lines were assessed by MTS assay. Interestingly, compound 2 exhibited particularly strong cytotoxic activities against HepG2, MCF7 and OVCAR8 cancer cell lines, with IC50 values of 3.20 ± 0.18, 3.10 ± 0.06 and 3.40 ± 0.007 µM, respectively. Furthermore, molecular docking simulations were carried out to explore the interactions and binding mechanisms of the most active compound (compound 2) with proteins. Our results contribute to understanding the secondary metabolites produced by S. dielsiana and provide a scientific rationale for further investigations of cytotoxicity of this valuable medicinal plant.


Asunto(s)
Alcaloides , Antineoplásicos Fitogénicos , Aporfinas , Simulación del Acoplamiento Molecular , Hojas de la Planta , Tallos de la Planta , Stephania , Aporfinas/química , Aporfinas/farmacología , Humanos , Hojas de la Planta/química , Tallos de la Planta/química , Alcaloides/química , Alcaloides/farmacología , Stephania/química , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/química , Estructura Molecular , Línea Celular Tumoral , Células Hep G2 , Células MCF-7 , Ensayos de Selección de Medicamentos Antitumorales , Espectroscopía de Resonancia Magnética , Plantas Medicinales/química
11.
Int J Mol Sci ; 25(9)2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38732218

RESUMEN

Boronate esters are a class of compounds containing a boron atom bonded to two oxygen atoms in an ester group, often being used as precursors in the synthesis of other materials. The characterization of the structure and properties of esters is usually carried out by UV-visible, infrared, and nuclear magnetic resonance (NMR) spectroscopic techniques. With the aim to better understand our experimental data, in this article, the density functional theory (DFT) is used to analyze the UV-visible and infrared spectra, as well as the isotropic shielding and chemical shifts of the hydrogen atoms 1H, carbon 13C and boron 11B in the compound 4-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde. Furthermore, this study considers the change in its electronic and spectroscopic properties of this particular ester, when its boron atom is coordinated with a fluoride anion. The calculations were carried out using the LSDA and B3LYP functionals in Gaussian-16, and PBE in CASTEP. The results show that the B3LYP functional gives the best approximation to the experimental data. The formation of a coordinated covalent B-F bond highlights the remarkable sensitivity of the NMR chemical shifts of carbon, oxygen, and boron atoms and their surroundings. Furthermore, this bond also highlights the changes in the electron transitions bands n → π* and π → π* during the absorption and emission of a photon in the UV-vis, and in the stretching bands of the C=C bonds, and bending of BO2 in the infrared spectrum. This study not only contributes to the understanding of the properties of boronate esters but also provides important information on the interactions and responses optoelectronic of the compound when is bonded to a fluorine atom.


Asunto(s)
Benzaldehídos , Benzaldehídos/química , Espectroscopía de Resonancia Magnética , Teoría Funcional de la Densidad , Flúor/química , Boro/química , Modelos Moleculares , Ésteres/química , Espectrofotometría Infrarroja , Estructura Molecular , Iones/química
12.
Int J Mol Sci ; 25(9)2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38732266

RESUMEN

Metabolic syndrome (MS) is a widespread disease in developed countries, accompanied, among others, by decreased adiponectin serum levels and perturbed lipoprotein metabolism. The associations between the serum levels of adiponectin and lipoproteins have been extensively studied in the past under healthy conditions, yet it remains unexplored whether the observed associations also exist in patients with MS. Therefore, in the present study, we analyzed the serum levels of lipoprotein subclasses using nuclear magnetic resonance spectroscopy and examined their associations with the serum levels of adiponectin in patients with MS in comparison with healthy volunteers (HVs). In the HVs, the serum levels of adiponectin were significantly negatively correlated with the serum levels of large buoyant-, very-low-density lipoprotein, and intermediate-density lipoprotein, as well as small dense low-density lipoprotein (LDL) and significantly positively correlated with large buoyant high-density lipoprotein (HDL). In patients with MS, however, adiponectin was only significantly correlated with the serum levels of phospholipids in total HDL and large buoyant LDL. As revealed through logistic regression and orthogonal partial least-squares discriminant analyses, high adiponectin serum levels were associated with low levels of small dense LDL and high levels of large buoyant HDL in the HVs as well as high levels of large buoyant LDL and total HDL in patients with MS. We conclude that the presence of MS weakens or abolishes the strong associations between adiponectin and the lipoprotein parameters observed in HVs and disturbs the complex interplay between adiponectin and lipoprotein metabolism.


Asunto(s)
Adiponectina , Voluntarios Sanos , Lipoproteínas , Síndrome Metabólico , Humanos , Adiponectina/sangre , Síndrome Metabólico/sangre , Masculino , Femenino , Persona de Mediana Edad , Adulto , Lipoproteínas/sangre , Lipoproteínas HDL/sangre , Estudios de Casos y Controles , Espectroscopía de Resonancia Magnética , Lipoproteínas LDL/sangre
13.
Folia Neuropathol ; 62(1): 13-20, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38741433

RESUMEN

The accurate diagnosis of brain tumour is very important in modern neuro-oncology medicine. Magnetic resonance spectroscopy (MRS) is supposed to be a promising tool for detecting cancerous lesions. However, the interpretation of MRS data is complicated by the fact that not all cancerous lesions exhibit elevated choline (Cho) levels. The main goal of our study was to investigate the lack of Cho lesion /Cho ref elevation in the population of grade II-III gliomas. 89 cases of gliomas grade II and III were used for the retrospective analysis - glioma (astrocytoma or oligodendroglioma) grade II (74 out of 89 cases [83%]) and III (15 out of 89 cases [17%]) underwent conventional MRI extended by MRS before treatment. Histopathological diagnosis was obtained either by biopsy or surgical resection. Gliomas were classified to the group of no-choline elevation when the ratio of choline measured within the tumour (Cho lesion ) to choline from NABT (Cho ref ) were equal to or lower than 1. Significant differences were observed between ratios of Cho lesion /Cr lesion calculated for no-choline elevation and glial tumour groups as well as in the NAA lesion /Cr lesion ratio between the no-choline elevation group and glial tumour group. With consistent data concerning choline level elevation and slightly lower NAA value, the Cho lesion /NAA lesion ratio is significantly higher in the WHO II glial tumour group compared to the no-choline elevation cases ( p < 0.000). In the current study the results demonstrated possibility of lack of choline elevation in patients with grade II-III gliomas, so it is important to remember that the lack of elevated choline levels does not exclude neoplastic lesion.


Asunto(s)
Neoplasias Encefálicas , Colina , Glioma , Humanos , Colina/metabolismo , Colina/análisis , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/metabolismo , Glioma/patología , Glioma/diagnóstico , Glioma/metabolismo , Persona de Mediana Edad , Adulto , Femenino , Masculino , Estudios Retrospectivos , Espectroscopía de Protones por Resonancia Magnética/métodos , Anciano , Espectroscopía de Resonancia Magnética/métodos , Clasificación del Tumor , Adulto Joven
14.
Int J Mol Sci ; 25(9)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38731888

RESUMEN

The interaction of heparin with antithrombin (AT) involves a specific sequence corresponding to the pentasaccharide GlcNAc/NS6S-GlcA-GlcNS3S6S-IdoA2S-GlcNS6S (AGA*IA). Recent studies have revealed that two AGA*IA-containing hexasaccharides, which differ in the sulfation degree of the iduronic acid unit, exhibit similar binding to AT, albeit with different affinities. However, the lack of experimental data concerning the molecular contacts between these ligands and the amino acids within the protein-binding site prevents a detailed description of the complexes. Differential epitope mapping (DEEP)-STD NMR, in combination with MD simulations, enables the experimental observation and comparison of two heparin pentasaccharides interacting with AT, revealing slightly different bound orientations and distinct affinities of both glycans for AT. We demonstrate the effectiveness of the differential solvent DEEP-STD NMR approach in determining the presence of polar residues in the recognition sites of glycosaminoglycan-binding proteins.


Asunto(s)
Antitrombinas , Heparina , Espectroscopía de Resonancia Magnética , Simulación de Dinámica Molecular , Oligosacáridos , Unión Proteica , Heparina/química , Heparina/metabolismo , Oligosacáridos/química , Oligosacáridos/metabolismo , Antitrombinas/química , Antitrombinas/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Sitios de Unión , Solventes/química , Mapeo Epitopo/métodos , Humanos
15.
Int J Mol Sci ; 25(9)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38731909

RESUMEN

Lung cancer is the leading cause of cancer-related mortality worldwide. In order to improve its overall survival, early diagnosis is required. Since current screening methods still face some pitfalls, such as high false positive rates for low-dose computed tomography, researchers are still looking for early biomarkers to complement existing screening techniques in order to provide a safe, faster, and more accurate diagnosis. Biomarkers are biological molecules found in body fluids, such as plasma, that can be used to diagnose a condition or disease. Metabolomics has already been shown to be a powerful tool in the search for cancer biomarkers since cancer cells are characterized by impaired metabolism, resulting in an adapted plasma metabolite profile. The metabolite profile can be determined using nuclear magnetic resonance, or NMR. Although metabolomics and NMR metabolite profiling of blood plasma are still under investigation, there is already evidence for its potential for early-stage lung cancer diagnosis, therapy response, and follow-up monitoring. This review highlights some key breakthroughs in this research field, where the most significant biomarkers will be discussed in relation to their metabolic pathways and in light of the altered cancer metabolism.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Pulmonares , Metabolómica , Humanos , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Biomarcadores de Tumor/sangre , Metabolómica/métodos , Detección Precoz del Cáncer/métodos , Metaboloma , Espectroscopía de Resonancia Magnética/métodos
16.
Cereb Cortex ; 34(5)2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38715406

RESUMEN

Presbycusis has been reported as related to cognitive decline, but its underlying neurophysiological mechanism is still unclear. This study aimed to investigate the relationship between metabolite levels, cognitive function, and node characteristics in presbycusis based on graph theory methods. Eighty-four elderly individuals with presbycusis and 63 age-matched normal hearing controls underwent magnetic resonance spectroscopy, functional magnetic resonance imaging scans, audiological assessment, and cognitive assessment. Compared with the normal hearing group, presbycusis patients exhibited reduced gamma-aminobutyric acid and glutamate levels in the auditory region, increased nodal characteristics in the temporal lobe and precuneus, as well as decreased nodal characteristics in the superior occipital gyrus and medial orbital. The right gamma-aminobutyric acid levels were negatively correlated with the degree centrality in the right precuneus and the executive function. Degree centrality in the right precuneus exhibited significant correlations with information processing speed and executive function, while degree centrality in the left medial orbital demonstrated a negative association with speech recognition ability. The degree centrality and node efficiency in the superior occipital gyrus exhibited a negative association with hearing loss and speech recognition ability, respectively. These observed changes indicate alterations in metabolite levels and reorganization patterns at the brain network level after auditory deprivation.


Asunto(s)
Disfunción Cognitiva , Imagen por Resonancia Magnética , Presbiacusia , Humanos , Masculino , Femenino , Presbiacusia/diagnóstico por imagen , Presbiacusia/metabolismo , Presbiacusia/fisiopatología , Anciano , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/fisiopatología , Espectroscopía de Resonancia Magnética , Ácido Glutámico/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Persona de Mediana Edad , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo
17.
Structure ; 32(5): 517-519, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38701749

RESUMEN

G-protein-coupled receptor (GPCR) activation relies on conformational sampling, a nuanced but functionally key behavior well suited to elucidation by nuclear magnetic resonance (NMR) spectroscopy. In this issue of Structure, Thakur et al.1 demonstrate that judicious choice of experimental conditions for 19F NMR studies of a GPCR enables rationalization of functional and pharmacological behavior, leading to testable hypotheses correlating structure, dynamics, and function.


Asunto(s)
Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Humanos , Resonancia Magnética Nuclear Biomolecular , Conformación Proteica , Espectroscopía de Resonancia Magnética/métodos
18.
Metabolomics ; 20(3): 50, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38722393

RESUMEN

INTRODUCTION: Analysis of time-resolved postprandial metabolomics data can improve our understanding of the human metabolism by revealing similarities and differences in postprandial responses of individuals. Traditional data analysis methods often rely on data summaries or univariate approaches focusing on one metabolite at a time. OBJECTIVES: Our goal is to provide a comprehensive picture in terms of the changes in the human metabolism in response to a meal challenge test, by revealing static and dynamic markers of phenotypes, i.e., subject stratifications, related clusters of metabolites, and their temporal profiles. METHODS: We analyze Nuclear Magnetic Resonance (NMR) spectroscopy measurements of plasma samples collected during a meal challenge test from 299 individuals from the COPSAC2000 cohort using a Nightingale NMR panel at the fasting and postprandial states (15, 30, 60, 90, 120, 150, 240 min). We investigate the postprandial dynamics of the metabolism as reflected in the dynamic behaviour of the measured metabolites. The data is arranged as a three-way array: subjects by metabolites by time. We analyze the fasting state data to reveal static patterns of subject group differences using principal component analysis (PCA), and fasting state-corrected postprandial data using the CANDECOMP/PARAFAC (CP) tensor factorization to reveal dynamic markers of group differences. RESULTS: Our analysis reveals dynamic markers consisting of certain metabolite groups and their temporal profiles showing differences among males according to their body mass index (BMI) in response to the meal challenge. We also show that certain lipoproteins relate to the group difference differently in the fasting vs. dynamic state. Furthermore, while similar dynamic patterns are observed in males and females, the BMI-related group difference is observed only in males in the dynamic state. CONCLUSION: The CP model is an effective approach to analyze time-resolved postprandial metabolomics data, and provides a compact but a comprehensive summary of the postprandial data revealing replicable and interpretable dynamic markers crucial to advance our understanding of changes in the metabolism in response to a meal challenge.


Asunto(s)
Metabolómica , Periodo Posprandial , Humanos , Periodo Posprandial/fisiología , Masculino , Femenino , Metabolómica/métodos , Adulto , Ayuno/metabolismo , Análisis de Componente Principal , Espectroscopía de Resonancia Magnética/métodos , Persona de Mediana Edad , Análisis de Datos , Metaboloma/fisiología
19.
Sci Rep ; 14(1): 10645, 2024 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724583

RESUMEN

Dyslipidaemias is the leading risk factor of several major cardiovascular diseases (CVDs), but there is still a lack of sufficient evidence supporting a causal role of lipoprotein subspecies in CVDs. In this study, we comprehensively investigated several lipoproteins and their subspecies, as well as other metabolites, in relation to coronary heart disease (CHD), heart failure (HF) and ischemic stroke (IS) longitudinally and by Mendelian randomization (MR) leveraging NMR-measured metabolomic data from 118,012 UK Biobank participants. We found that 123, 110 and 36 analytes were longitudinally associated with myocardial infarction, HF and IS (FDR < 0.05), respectively, and 25 of those were associated with all three outcomes. MR analysis suggested that genetically predicted levels of 70, 58 and 7 analytes were associated with CHD, HF and IS (FDR < 0.05), respectively. Two analytes, ApoB/ApoA1 and M-HDL-C were associated with all three CVD outcomes in the MR analyses, and the results for M-HDL-C were concordant in both observational and MR analyses. Our results implied that the apoB/apoA1 ratio and cholesterol in medium size HDL were particularly of importance to understand the shared pathophysiology of CHD, HF and IS and thus should be further investigated for the prevention of all three CVDs.


Asunto(s)
Enfermedades Cardiovasculares , Análisis de la Aleatorización Mendeliana , Humanos , Enfermedades Cardiovasculares/genética , Masculino , Femenino , Factores de Riesgo , Persona de Mediana Edad , Espectroscopía de Resonancia Magnética/métodos , Apolipoproteína A-I/sangre , Apolipoproteína A-I/genética , Anciano , HDL-Colesterol/sangre , Enfermedad Coronaria/genética , Metabolómica/métodos , Apolipoproteína B-100/genética , Accidente Cerebrovascular Isquémico/genética , Accidente Cerebrovascular Isquémico/sangre , Accidente Cerebrovascular Isquémico/epidemiología , Insuficiencia Cardíaca/genética
20.
Metabolomics ; 20(3): 58, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773056

RESUMEN

INTRODUCTION: Bio stimulants are substances and/or microorganisms that are used to improve plant growth and crop yields by modulating physiological processes and metabolism of plants. While research has primarily focused on the broad effects of bio stimulants in crops, understanding their cellular and molecular influences in plants, using metabolomic analysis, could elucidate their effectiveness and offer possibilities for fine-tuning their application. One such bio stimulant containing galacturonic acid as elicitor is used in agriculture to improve wheat vigor and strengthen resistance to lodging. OBJECTIVE: However, whether a metabolic response is evolved by plants treated with this bio stimulant and the manner in which the latter might regulate plant metabolism have not been studied. METHOD: Therefore, the present study used 1H-NMR and LC-MS to assess changes in primary and secondary metabolites in the roots, stems, and leaves of wheat (Triticum aestivum) treated with the bio stimulant. Orthogonal partial least squares discriminant analysis effectively distinguished between treated and control samples, confirming a metabolic response to treatment in the roots, stems, and leaves of wheat. RESULTS: Fold-change analysis indicated that treatment with the bio stimulation solution appeared to increase the levels of hydroxycinnamic acid amides, lignin, and flavonoid metabolism in different plant parts, potentially promoting root growth, implantation, and developmental cell wall maturation and lignification. CONCLUSION: These results demonstrate how non-targeted metabolomic approaches can be utilized to investigate and monitor the effects of new agroecological solutions based on systemic responses.


Asunto(s)
Metabolómica , Triticum , Triticum/metabolismo , Triticum/efectos de los fármacos , Metabolómica/métodos , Cromatografía Liquida/métodos , Espectrometría de Masas/métodos , Espectroscopía de Resonancia Magnética/métodos , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de los fármacos , Raíces de Plantas/metabolismo , Raíces de Plantas/efectos de los fármacos , Cromatografía Líquida con Espectrometría de Masas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA