Transition metals (TMs) are found in the core of several phenomena such as catalysis, folding, assembly, and (bio)molecular recognition and are directly involved in a number of diseases from cancer to neurodegenerative disorders. The variety of oxidation and spin states displayed by TMs makes them a versatile tool to take part in a large number of biological processes. Metal ions stabilize permanent and transient protein-protein interactions in both natural and artificially designed proteins and are the drivers of metal-directed protein folding. The presence of metal ions or metal cofactors in the active site of enzymes remarkably enhances the diversity of functions displayed by these biomolecules.
Understanding how a substrate/drug binds to a biological receptor, how proteins assemble and interact with each other, how lipids and proteins aggregate in membranes, and how these events trigger or block a wide range of biochemical reactions is of paramount importance. The role of TMs in all of these events and its implications for diseases or (bio)catalyst and drug design is the goal of this project in the long-term. The aim of the current proposal is to design a computational approach to lay the foundations for the study of these phenomena.
Therefore, the main aim of the MetAccembly project is to design a computational approach that pave the way for studying the nature of these metal dependent processes at the atomic level and with a reasonable computational cost. Particularly in the last decade, molecular dynamics simulations of large biomolecules have undergone a step forward because of the increase in computational power and algorithms translating to longer and more accurate simulations going beyond the microsecond time scale. However, conventional MD simulations are associated with a high computational cost for describing biological events such as assembly, folding, or molecular recognition that take place in long time scales involving slow conformational changes that require milliseconds to be completed. There is a need for new techniques that speed up these processes. In this project, we focus our attention on accelerated molecular dynamics (aMD), a versatile enhanced sampling technique that speeds up molecular dynamics and does not rely on the a priori definition of reaction coordinates. This method has shown promising results in the field of protein dynamics and drug discovery.
In this project, we reformulated aMD with special focus on the fine-tuning of acceleration parameters and apply it to describe in detail the processes of assembly and biomolecular recognition. The new method has been assessed for a large number of different systems that involve protein folding, assembly of proteins and nanotubes, supramolecular host-guest systems, peptide assembly, and redox driven folding and recognition in metalloproteins.