La unidad dispone de un equipo Biacore X-100 y de un Microcal PeaQ-ITC que permiten detectar y monitorizar interacciones entre dos o más moléculas en tiempo real sin emplear ningún tipo de marcaje. El tipo de interacciones estudiadas pueden ser: proteína-proteína, proteína-péptido, proteína-molécula pequeña, péptido-péptido y ADN-molécula pequeña. Los experimentos que pueden llevarse a cabo permiten determinar la especificidad entre dos o más ligandos y/o caracterizar la cinética y afinidad de dicha interacción. Con el análisis de los datos se obtienen las constantes de velocidad así como las de asociación/disociación del complejo formado (SPR). También se puede determinar la Kd, entalpía y entropía de la interacción mediante microcalorimetría (ITC).
Surface plasmon resonance
The Unit belongs to the Medicinal Chemistry Institute (IQM) and gives support to the researcher of the IQM, CSIC, as well as other Research Organism (Universities, OPIs, private Research Centers, etc). The SPR Unit has a Biacore X-100 to detect and monitorize interactions between two or more molecules in real time without labeling. The kind of interactions to study are: protein-protein, protein-peptide, protein-small molecule, peptide-peptide and DNA-small molecule. The experiments allow to calculate the specifity between two or more ligands and/or to characterize the kinetics and affinities of the interaction. The data analysis allows calculating the rate constant and the association/dissociation constants of the complex. SPR is a relatively new technique with high impact in the Medicinal Chemistry and Chemical Biology field. Due to its high sensitivity, it is possible to measure direct binding in a real time between two ligands of nearly any molecular system being nowadays a technique which applications have been expanded well beyond target characterization to support screening and lead optimization. The SPR condition services can be split in five steps that are summarizes below: - Experimental design. Due to the versatility of our equipment, a detailed and particular design of the experiments is done. This design could be of different nature based on the type of interaction and the initial condition of the samples to be investigated. To do a preliminary study of the interaction system will be crucial to get good results. -Buffer preparation. It is done by the service, and they are always filtrated following the system and equipment requirements. -Measures. At this stage, a rigorous methodology is used together with a quality commitment during the sample preparation and the measurements. It is a prerequisite the filtration of the samples, and it is also really important the 'in situ' preparation of the samples. Regarding the assay, the measures are always done by triplicate as guarantee of the reliability of the results. Also, in each experiment the necessary controls to confirm the optimal development of the experiment are included. -Evaluation. The evaluation will be done using the software of the Biacore X-100 that has the equations and the adjustment models necessary to obtain high quality results in a short time. -Report. The report will summarize the detailed study of the molecular interaction, as well as kinetic and/or thermodynamic parameters. The kinetic analysis will detail the binding values of the interaction and, when it will be possible, the association/dissociation rate constants. Furthermore, the stoichiometry and the model of the interaction will be included. The obtained information during the equilibrium measures will allow the calculation of the affinity constant.