Group Leader/s

 

intro

The nuclear magnetic resonance (NMR) group, under the leadership of Prof. Francisco Javier Cañada Vicinay is interested in the development of general methodological aspects of the NMR techniques and, in particular, in their applications to the study of the conformation and dynamics of the molecular recognition processes.
 
During the last few years we have determined the solution 3D structure of different proteins using a protocol based on NMR spectroscopy, assisted by molecular mechanics and dynamics calculations.This methodology has been applied to different carbohydrate molecular complexes of wild type and mutant lectins and glycosidases, and to the elucidation of the structure of other protein receptors of biomedical interest. We have investigated protein complexes with natural ligands as well as synthetically modified analogues.
We have also investigated the structural characteristics, both from the conformational and dynamical point of view, of different biologically relevant oligo and polysaccharides following the same methodology involving NMR and molecular dynamics. In particular, we have paid attention to the physical-chemical origin of the interaction between carbohydrates and proteins, with special emphasis in the relative role of sugar-aromatic stacking interactions.
Natural abundance as well as labeled ligands and proteins (13C, 15N) have been used for these studies.
 
Thanks to the collaboration with several research groups throughout the world, some studied systems include galectins, in which we are deeply involved, as well as hevein domains, ricin-B, viscumin, lactase, ribonuclease B, DC-SIGN, acidic fibroblast growth factor, cholera toxin B, glycomimetics, C- and S-glycosyl compounds, aminoglycosides, carbohydrate antigens, bacterial and fungal polysaccharides, etc.
We are also interested in the determination of the enzyme UDP-glucose pyrophosphorylase, a key component of the pneumococcal cell capsule in all the known strains of this bacterium. The group collaborates with numerous Spanish and foreign research laboratories in numerous other projects not directly related with its main research goals.

Finally, we would like to mention that Prof. J. Jiménez Barbero, who shared the leadership of the group with Prof. Cañada since 2002, moved at the end of 2014 to CICbioGune (Bizcaia, Spain), with new responsibilities as Scientific Director.

 

Mónico, A. Martínez-Senra, E., Cañada, FJ. Zorrilla, S. Pérez-Sala, D.  [2017]. Drawbacks of Dialysis Procedures for Removal of EDTA. PLoS One. 18, 12

 

Funding

Rompiendo las fronteras del reconocimiento molecular de carbohidratos mediante RMN. Proteínas, anticuerpos y acidos nucleicos.

MINECO, CTQ2015-64597-C2-2-P 2016-2018

 

Nueva vacuna antineoplásica basada en el carbohidrato tumoral Ca10

MINECO, RETOS COLABORACIÓN, RTC-2015-3805-1 01/11/2015 Hasta: 31/10/2018

Coordinador: Empresa INMUNOTEK

 

El proyecto está siendo financiado con fondos FEDER, con el objetivo de promover el desarrollo tecnológico, la innovación y una investigación de calidad

 

RMN y reconocimiento molecular. Interacciones Proteina-Carbohidrato y ácido nucleico-carbohidrato

MECC CTQ2012-32025 --enero 2013-diciembre 2015

 

 

More info

During last years, we have contributed to the study of diverse molecular recognition processes of sugars by lectins, enzymes, antibodies and nucleic acids. These studies have been disseminated to the Society on a number of publications, book chapters and reviews and on many lectures at symposia and institutions. Also, all PhD and Postdoctoral associates have presented several dozens of posters and oral communications at National and International symposia. We have performed rigorous analysis of the interactions which take place at a variety of binding sites on different systems and, in some cases, deduced the thermodynamic parameters of the interactions. Generalization is still difficult and more work seems necessary also to define the importance of motion and dynamics for the interaction to take place and to make use of the knowledge to effectively design better ligands and inhibitors. We have employed till now model lectins and synthetic models (artificial lectins) as well as designed saccharides to interact with nucleic acids. We have pioneered the use of trNOE to deduce the bioactive conformation of saccharides and glycomimetics and the employment of STD experiments to validate the ligand epitope. We have demonstrated that in most cases, by employing flexible ligands, the architecture of the binding site rules the recognition process and that the same analogue might be recognized in three different geometries by three distinct receptors. Also, in the glycosidase context, we have determined for the first time, the bioactive conformation of a competitive inhibitor bound to an enzyme in solution as well as the bound conformation of a natural substrate to a mutated inactive enzyme. Indeed, we demonstrated that the enzyme selects a high energy conformation of the substrate, within the pathway towards the transition state to minimize the energy needs for the hydrolysis to take place. From the viewpoint of the conformational study of sugars, glycomimetics, lectins and their interactions, we have performed key developments and Concepts that have been recognized by invitations in different forums. The first NMR structure in solution of a lectin/sugar complex was published by us, as well as the first experimental characterization of the energy value of the stereoelectronic component of the exo-anomeric effect. Also, we have recently provided definitive proof of the importance of CH-pi interactions for sugar recognition by receptors. From the methodology viewpoint we have been the first group to demonstrate that intact cells may be employed to deduce binding features of the interactions between receptors and ligands, without prior requirement of purification of the protein. New developments are hopefully expected from our group.

Team. At present: 3 PhD students, 1 post-docs, 1 full professors. The group has trained 13 PhD students in the last 10 years. The research group in Madrid has a long-standing experience and international reputation in the application of NMR methods to the study of the three dimensional structure of proteins and their complexes with carbohydrates and glycomimetics. Apart of NMR, the team has also access to other techniques, which may allow deducing other physicochemical parameters relevant to the study of intermolecular interactions.

Prof J. Cañada (PhD in Chemistry) is full Professor from CSIC from 2007. He has published more than 100 publications and has delivered a variety of lectures at national and international meetings and Institutions. He has supervised 5 PhD Thesis. His expertise is in the molecular recognition, NMR, biochemistry and molecular biology fields.