Conformación tridimensional y reconocimiento molecular de biopolímeros : aplicación de RMN multidimensional y desarrollo de metodología de cálculo y estructural

El objetivo principal de la Tesis ha sido la exploración, el análisis y el perfeccionamiento de las técnicas más habituales utilizadas en la determinación de la estructura y dinámica de biopolímeros en disolución. En concreto, se han utilizado métodos teóricos y experimentales para obtener las estructuras de dos biopolímeros entre los grupos más numerosos de ellos: proteínas y ácidos nucleicos. La obtención de la estructura de una proteína de interés bioquímico por sus peculiaridades cinéticas mediante dos técnicas diferentes ha sido uno de los objetivos principales en la Tesis. La aplicación de las técnicas de modelización por homología y la realización de un análisis exhaustivo sobre los factores que afectan a la calidad del método permitirá aportar la obtención de mejores estructuras de proteínas mediante el uso de esta técnica. La determinación de la estructura de la Plastocianina mediante un método teórico como es la modelización por homología y otro experimental como es la RMN permitirá evaluar el grado de convergencia entre ambas y sopesar la validez de las técnicas teóricas como medio de ampliación de las estructuras de proteínas caracterizadas. La aplicación del formalismo libre de modelo de Lipari-Szabo al análisis de los procesos de relajación en RMN mediante la confección de un programa escrito en C permitirá aportar mayor objetividad al estudio de la dinámica de proteína mediante técnicas de RMN. El estudio de sistemas cuya dinámica ha sido analizada previamente mediante el uso de otros programas diferentes y la comparación con los resultados obtenidos permitirá conocer la validez tanto de la aproximación empleada como del algoritmo programado. El análisis de la dinámica de una proteína tan bien estudiada como el wt-BPTI (Inhibidor Básico de la Tripsina de Páncreas Bovina en forma nativa) frente a uno de sus mutantes constituye un ejemplo de análisis exhaustivo de la dinámica de una proteína mediante relajación en RMN. El desarrollo de las rutinas aplicadas en el programa HYPER para la obtención de restricciones de ángulos diedros en la cadena principal y en las cadenas laterales mediante la utilización de información de NOEs y constantes de acoplamiento escalar constituye un ejemplo de la dirección a seguir en el refinamiento de estructuras de RMN. La novedosa metodología utilizada en la determinación del ángulo diedro mediante el análisis de intensidades TOCSY (espectroscopía de correlación total) frente al tiempo de mezcla del experimento, incluso para residuos sin dos protones metilénicos como las treoninas y su aplicación a una proteína cuya estructura ya ha sido determinada, permite evaluar la importancia del desarrollo de metodologías similares en el refinamiento de estructuras por RMN. Por último, la determinación de la estructura de un oligonucleótido en disolución mediante RMN utilizando las técnicas de simulación de picos DQF-COSY (Espectroscopía de Correlación Escalar con Filtro de Doble Cuanto) y su comparación con la estructura determinada mediante rayos X, confirma el interés que presentan las estructuras en disolución de bio-polímeros y las sustanciales diferencias que pueden presentar frente a las estructuras cristalinas determinadas mediante difracción de rayos X. Asimismo, la estructura del d(CCGCGG) es un ejemplo de la influencia de la secuencia nucleotídica en la conformación local de cadenas de ADN

Healthy lifestyle, metabolomics and incident type 2 diabetes in a population-based cohort from Spain

This work was supported by the Strategic Action for Research in Health sciences [PI10/0082, PI13/01848, PI14/00874, PI16/01402, PI11/00726, PI16/609, PI16/1512, PI18/287, PI19/319 and PI20/00896], the GUTMOM Project (JPI-A Healthy Diet for a Healthy Life INTIMIC-085, State Secretary of R + D + I PCIN-2017-117), the Cátedra de Epidemiología y Control del Riesgo Cardiovascular at UAM (#820024), the State Agency for Research (PID2019-108973RB-C21 and C22), the Valencia Government (GRUPOS 03/101; PROMETEO/2009/029 and ACOMP/2013/039), the Castilla-Leon Government (GRS/279/A/08) and European Network of Excellence Ingenious Hypercare (EPSS- 037093) from the European Commission; CIBER Fisiopatología Obesidad y Nutrición (CIBEROBN) (CIBER-02-08-2009, CB06/03 and CB12/03/30016). MSP holds a Ramón y Cajal contract (RYC-2018-025069-I) from the Ministry of Science, Innovation and Universities. MDV holds a “Predoctoral Training in Health Research” contract (FI20/00162) from the Carlos III Health Institute. MGP and ADR received the support of a fellowship from “la Caixa” Foundation (ID 100010434, fellowship codes LCF/BQ/IN18/11660001, and LCF/BQ/DR19/11740016, respectively). PO received the support of a Sara Borrell contract from the Carlos III Health Institute (reference CD16/00255). The Strategic Action for Research in Health Sciences, CIBEROBN are initiatives from Carlos III Health Institute Madrid and co-funded by the European Social Fund “The ESF - investing in your future”. The State Agency for Research and Carlos III Health Institute belong to the Spanish Ministry of Science and Innovation. The funding bodies had no role in the study design, data collection and analysis, interpretation of results, manuscript preparation or in the decision to submit this manuscript for publication.Background: The contribution of metabolomic factors to the association of healthy lifestyle with type 2 diabetes risk is unknown. We assessed the association of a composite measure of lifestyle with plasma metabolite profiles and incident type 2 diabetes, and whether relevant metabolites can explain the prospective association between healthy lifestyle and incident type 2 diabetes. Methods: A Healthy Lifestyle Score (HLS) (5-point scale including diet, physical activity, smoking status, alcohol consumption and BMI) was estimated in 1016 Hortega Study participants, who had targeted plasma metabolomic determinations at baseline examination in 2001–2003, and were followed-up to 2015 to ascertain incident type 2 diabetes. Results: The HLS was cross-sectionally associated with 32 (out of 49) plasma metabolites (2.5% false discovery rate). In the subset of 830 participants without prevalent type 2 diabetes, the rate ratio (RR) and rate difference (RD) of incident type 2 diabetes (n cases = 51) per one-point increase in HLS was, respectively, 0.69 (95% CI, 0.51, 0.93), and − 8.23 (95% CI, − 16.34, − 0.13)/10,000 person-years. In single-metabolite models, most of the HLS-related metabolites were prospectively associated with incident type 2 diabetes. In probit Bayesian Kernel Machine Regression, these prospective associations were mostly driven by medium HDL particle concentration and phenylpropionate, followed by small LDL particle concentration, which jointly accounted for ~ 50% of the HLS-related decrease in incident type 2 diabetes. Conclusions: The HLS showed a strong inverse association with incident type 2 diabetes, which was largely explained by plasma metabolites measured years before the clinical diagnosis.CIBER Fisiopatología Obesidad y NutriciónCastilla-Leon Government GRS/279/A/08European Network of Excellence Ingenious Hypercare EPSS- 037093State Agency for Research ACOMP/2013/039, GRUPOS 03/101, PROMETEO/2009/029Strategic Action for Research in Health sciences INTIMIC-085, PCIN-2017-117Ministerio de Ciencia, Innovación y Universidades RYC-2018-025069-IEuropean Commission EPSS-037093Instituto de Salud Carlos III CB06/03, CB12/03/30016, CD16/00255, CIBER-02-08-2009, PI10/0082, PI11/00726, PI13/01848, PI14/00874, PI16/01402, PI16/1512, PI16/609, PI18/287, PI19/319, PI20/00896Universidad Autónoma de Madrid 820024Agencia Estatal de Investigación PID2019-108973RB-C21“La Caixa” Foundation 100010434, LCF/BQ/DR19/11740016, LCF/BQ/IN18/1166000

Conformation and concerted dynamics of the integrin-binding site and the C-terminal region of echistatin revealed by homonuclear NMR

Echistatin is a potent antagonist of the integrins αvβ3, α5β1 and αIIbβ3. Its full inhibitory activity depends on an RGD (Arg-Gly- Asp) motif expressed at the tip of the integrin-binding loop and on its C-terminal tail. Previous NMR structures of echistatin showed a poorly defined integrin-recognition sequence and an incomplete C-terminal tail, which left the molecular basis of the functional synergy between the RGD loop and the C-terminal region unresolved. We report a high-resolution structure of echistatin and an analysis of its internal motions by off-resonance ROESY (rotating-frame Overhauser enhancement spectroscopy). The fulllength C-terminal polypeptide is visible as a β-hairpin running parallel to the RGD loop and exposing at the tip residues Pro43, His44 and Lys45. The side chains of the amino acids of the RGD motif have well-defined conformations. The integrin-binding loop displays an overall movement with maximal amplitude of 30◦. Internal angular motions in the 100–300 ps timescale indicate increased flexibility for the backbone atoms at the base of the integrin- recognition loop. In addition, backbone atoms of the amino acids Ala23 (flanking the R24GD26 tripeptide) and Asp26 of the integrin-binding motif showed increased angular mobility, suggesting the existence of major and minor hinge effects at the base and the tip, respectively, of the RGD loop. A strong network of NOEs (nuclear Overhauser effects) between residues of the RGD loop and the C-terminal tail indicate concerted motions between these two functional regions. A full-length echistatin– αvβ3 docking model suggests that echistatin’s C-terminal amino acids may contact αv-subunit residues and provides new insights to delineate structure–function [email protected]; [email protected]; [email protected]; [email protected]

Metabolic Profile of chronic liver disease by NMR spectroscopy of human biopsies

Abstract Among the different processes occurring during the evolution of liver disease, fibrosis has a predominant role. Liver fibrosis mechanisms are fairly constant irrespective of the underlying etiology. Cirrhosis is the end-stage of this reaction. Metabolic profiles, which are affected by many physiological and pathological processes, may provide further insight into the metabolic consequences of this severe liver disease. The aim of this study was to demonstrate the applicability of 1H high resolution magic angle spinning (HR-MAS) NMR spectroscopy in the biochemical profile determination of human liver needle biopsy samples for the characterization of metabolic alterations related to the severity of liver disease. We recorded and analyzed HR-MAS spectra of 68 liver tissue samples obtained by needle biopsy from patients with chronic liver disease. Multivariate analysis was applied to these data to obtain discrimination patterns and to reveal relevant metabolites. The metabolic characterization of liver tissue from needle biopsies by HR-MAS NMR spectroscopy provided differential patterns for cirrhotic and non-cirrhotic chronic liver disease tissue. Metabolites closely related to the liver metabolism such as some fatty acids, glucose and amino acids show differences between the two groups. Phospholipid precursors, which have been previously correlated with hepatic lesions also show differences. Furthermore, the correlation between histologically assessed liver disease stages and the levels of the most discriminative metabolites show that liver dysfunction is present at the initial stages of chronic hepatic lesions. Overall, this work suggests that the additional information obtained by NMR metabolomics applied to needle biopsies of human liver may be useful for assessing metabolic alterations and liver dysfunction in chronic liver disease

Healthy lifestyle, metabolomics and incident type 2 diabetes in a population-based cohort from Spain

Background: The contribution of metabolomic factors to the association of healthy lifestyle with type 2 diabetes risk is unknown. We assessed the association of a composite measure of lifestyle with plasma metabolite profiles and incident type 2 diabetes, and whether relevant metabolites can explain the prospective association between healthy lifestyle and incident type 2 diabetes. Methods: A Healthy Lifestyle Score (HLS) (5-point scale including diet, physical activity, smoking status, alcohol consumption and BMI) was estimated in 1016 Hortega Study participants, who had targeted plasma metabolomic determinations at baseline examination in 2001-2003, and were followed-up to 2015 to ascertain incident type 2 diabetes. Results: The HLS was cross-sectionally associated with 32 (out of 49) plasma metabolites (2.5% false discovery rate). In the subset of 830 participants without prevalent type 2 diabetes, the rate ratio (RR) and rate difference (RD) of incident type 2 diabetes (n cases = 51) per one-point increase in HLS was, respectively, 0.69 (95% CI, 0.51, 0.93), and - 8.23 (95% CI, - 16.34, - 0.13)/10,000 person-years. In single-metabolite models, most of the HLS-related metabolites were prospectively associated with incident type 2 diabetes. In probit Bayesian Kernel Machine Regression, these prospective associations were mostly driven by medium HDL particle concentration and phenylpropionate, followed by small LDL particle concentration, which jointly accounted for ~ 50% of the HLS-related decrease in incident type 2 diabetes. Conclusions: The HLS showed a strong inverse association with incident type 2 diabetes, which was largely explained by plasma metabolites measured years before the clinical diagnosis.This work was supported by the Strategic Action for Research in Health sciences [PI10/0082, PI13/01848, PI14/00874, PI16/01402, PI11/00726, PI16/609, PI16/1512, PI18/287, PI19/319 and PI20/00896], the GUTMOM Project (JPI-A Healthy Diet for a Healthy Life INTIMIC-085, State Secretary of R + D + I PCIN-2017-117), the Cátedra de Epidemiología y Control del Riesgo Cardiovascular at UAM (#820024), the State Agency for Research (PID2019-108973RB-C21 and C22), the Valencia Government (GRUPOS 03/101; PROMETEO/2009/029 and ACOMP/2013/039), the Castilla-Leon Government (GRS/279/A/08) and European Network of Excellence Ingenious Hypercare (EPSS- 037093) from the European Commission; CIBER Fisiopatología Obesidad y Nutrición (CIBEROBN) (CIBER-02-08-2009, CB06/03 and CB12/03/30016). MSP holds a Ramón y Cajal contract (RYC-2018-025069-I) from the Ministry of Science, Innovation and Universities. MDV holds a “Predoctoral Training in Health Research” contract (FI20/00162) from the Carlos III Health Institute. MGP and ADR received the support of a fellowship from “la Caixa” Foundation (ID 100010434, fellowship codes LCF/BQ/IN18/11660001, and LCF/BQ/DR19/11740016, respectively). PO received the support of a Sara Borrell contract from the Carlos III Health Institute (reference CD16/00255). The Strategic Action for Research in Health Sciences, CIBEROBN are initiatives from Carlos III Health Institute Madrid and co-funded by the European Social Fund “The ESF - investing in your future”. The State Agency for Research and Carlos III Health Institute belong to the Spanish Ministry of Science and Innovation. The funding bodies had no role in the study design, data collection and analysis, interpretation of results, manuscript preparation or in the decision to submit this manuscript for publication.S

Temas Biologia Medicina en ingles

El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de ValènciaTemas de la asignatura de Biologia Primero medicine en inglés