de la Morena-Barrio M.E.,University of Murcia |
Buil A.,InstitutdInvestigacio Sant Pau IIB Sant |
Anton A.I.,University of Murcia |
Martinez-Martinez I.,University of Murcia |
And 9 more authors.
PLoS ONE | Year: 2013
The haemostatic relevance of antithrombin together with the low genetic variability of SERPINC1, and the high heritability of plasma levels encourage the search for modulating genes. We used a hypothesis-free approach to identify these genes, evaluating associations between plasma antithrombin and 307,984 polymorphisms in the GAIT study (352 individuals from 21 Spanish families). Despite no SNP reaching the genome wide significance threshold, we verified milder positive associations in 307 blood donors from a different cohort. This validation study suggested LARGE, a gene encoding a protein with xylosyltransferase and glucuronyltransferase activities that forms heparin-like linear polysaccharides, as a potential modulator of antithrombin based on the significant association of one SNPs, rs762057, with anti-FXa activity, particularly after adjustment for age, sex and SERPINC1 rs2227589 genotype, all factors influencing antithrombin levels (p = 0.02). Additional results sustained this association. LARGE silencing inHepG2 and HEK-EBNA cells did not affect SERPINC1 mRNA levels but significantly reduced the secretion of antithrombin with moderate intracellular retention. Milder effects were observed on α1-antitrypsin, prothrombin and transferrin. Our study suggests LARGE as the first known modifier of plasma antithrombin, and proposes a new role for LARGE in modulating extracellular secretion of certain glycoproteins. © 2013 de la Morena-Barrio et al.
Maier T.,EMBL CRG Systems Biology Research Unit |
Maier T.,University Pompeu Fabra |
Marcos J.,University Pompeu Fabra |
Marcos J.,Bio analysis Group |
And 11 more authors.
Molecular BioSystems | Year: 2013
Systems metabolomics, the identification and quantification of cellular metabolites and their integration with genomics and proteomics data, promises valuable functional insights into cellular biology. However, technical constraints, sample complexity issues and the lack of suitable complementary quantitative data sets prevented accomplishing such studies in the past. Here, we present an integrative metabolomics study of the genome-reduced bacterium Mycoplasma pneumoniae. We experimentally analysed its metabolome using a cross-platform approach. We explain intracellular metabolite homeostasis by quantitatively integrating our results with the cellular inventory of proteins, DNA and other macromolecules, as well as with available building blocks from the growth medium. We calculated in vivo catalytic parameters of glycolytic enzymes, making use of measured reaction velocities, as well as enzyme and metabolite pool sizes. A quantitative, inter-species comparison of absolute and relative metabolite abundances indicated that metabolic pathways are regulated as functional units, thereby simplifying adaptive responses. Our analysis demonstrates the potential for new scientific insight by integrating different types of large-scale experimental data from a single biological source. © The Royal Society of Chemistry 2013.
Wodke J.A.H.,EMBL CRG Systems Biology Research Unit |
Wodke J.A.H.,University Pompeu Fabra |
Wodke J.A.H.,Humboldt University of Berlin |
Puchalka J.,Helmholtz Center for Infection Research |
And 20 more authors.
Molecular Systems Biology | Year: 2013
Mycoplasma pneumoniae, a threatening pathogen with a minimal genome, is a model organism for bacterial systems biology for which substantial experimental information is available. With the goal of understanding the complex interactions underlying its metabolism, we analyzed and characterized the metabolic network of M. pneumoniae in great detail, integrating data from different omics analyses under a range of conditions into a constraint-based model backbone. Iterating model predictions, hypothesis generation, experimental testing, and model refinement, we accurately curated the network and quantitatively explored the energy metabolism. In contrast to other bacteria, M. pneumoniae uses most of its energy for maintenance tasks instead of growth. We show that in highly linear networks the prediction of flux distributions for different growth times allows analysis of time-dependent changes, albeit using a static model. By performing an in silico knock-out study as well as analyzing flux distributions in single and double mutant phenotypes, we demonstrated that the model accurately represents the metabolism of M. pneumoniae. The experimentally validated model provides a solid basis for understanding its metabolic regulatory mechanisms. © 2013 EMBO and Macmillan Publishers Limited.
Defaus S.,University Pompeu Fabra |
Defaus S.,Bio analysis Group |
Gupta P.,Bio analysis Group |
Andreu D.,University Pompeu Fabra |
And 2 more authors.
Analyst | Year: 2014
Carbohydrates fulfil many common as well as extremely important functions in nature. They show a variety of molecular displays-e.g., free mono-, oligo-, and polysaccharides, glycolipids, proteoglycans, glycoproteins, etc.-with particular roles and localizations in living organisms. Structure-specific peculiarities are so many and diverse that it becomes virtually impossible to cover them all from an analytical perspective. Hence this manuscript, focused on mammalian glycosylation, rather than a complete list of analytical descriptors or recognized functions for carbohydrate structures, comprehensively reviews three central issues in current glycoscience, namely (i) structural analysis of glycoprotein glycans, covering both classical and novel approaches for teasing out the structural puzzle as well as potential pitfalls of these processes; (ii) an overview of functions attributed to carbohydrates, covering from monosaccharide to complex, well-defined epitopes and full glycans, including post-glycosylational modifications, and (iii) recent technical advances allowing structural identification of glycoprotein glycans with simultaneous assignation of biological functions. © the Partner Organisations 2014.
Jimenez-Castells C.,University Pompeu Fabra |
Defaus S.,University Pompeu Fabra |
Moise A.,University of Konstanz |
Przbylski M.,University of Konstanz |
And 3 more authors.
Analytical Chemistry | Year: 2012
Interest in powerful, nanosized tools to analyze in detail glycan-protein interactions has increased significantly over recent years. Here, we report two complementary approaches to characterize such interactions with high sensitivity, low sample consumption, and without the need for sample labeling, namely, surface plasmon resonance (SPR) and an approach that combines limited proteolysis and mass spectrometry. Combination of these two approaches to investigate glycan-protein interactions allows (1) to characterize interactions through kinetic and thermodynamic parameters, (2) to capture efficiently the carbohydrate-binding protein, and (3) to identify the interacted protein and its carbohydrate binding site by mass spectrometry. As a proof of principle, the interaction of the galactose-specific legume lectin Erythrina cristagalli agglutinin with several sugars has been characterized in-depth by means of these two approaches. © 2012 American Chemical Society.