NMR Protein-Ligand Interaction Studies under Non-Homogeneous Conditions for Biomaterial Generation: A Model For Artificial Lectin-Carbohydrate Recognition

Smart biomaterials for tissue regeneration need to incorporate molecules able to interact with specific cellular adhesion or morphogenic proteins of the extracellular matrix (ECM).NMR binding studies allow obtaining structural information essential for the comprehension of biological processes and, nowadays, high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy is a well-established tool for the study of heterogeneous systems. Here the generation of a model-system used to explore the possibility to reveal interactions between two molecular entities, one of which linked to a solid support, to mimic a bioactive species immobilized on a biomaterial surface, is presented. The carbohydrate recognition processes that take place in the ECM have a pivotal role in promoting cell adhesion and differentiation and, thus, tissue regeneration. Hence, a pseudo-receptor, that mimics the lectin binding site was prepared and its interaction with a panel of different monosaccharides was characterized. The results obtained support the theoretical model according to which lectins bind carbohydrates exploiting the CH-π interactions occurring in their active site. Moreover the NMR experimental approach here described can be generally applied when the interacting species do not have the same solubility properties in physiological conditions and, in particular, can be exploited for the analysis and characterization of molecular recognition events occurring at biomaterial surface.