NON-EQ-SA

The NON-EQ-SA project (March 2014– Feb 2018) was funded by a MC-Career Integration Grant under the 7th framework (FP7).

Summary:

The long term goal of the Laboratory of Non-equilibrium Complex Systems (founded by the fellow of this Marie Curie Career Integration Grant entitled “NON-EQ-SA”) is to obtain adaptive, self-healing, self-replicating and ultimately “living” synthetic systems using molecular self-assembly under far-from-equilibrium conditions. In this NON-EQ-SA grant two projects have been proposed: 1) using biological building blocks (specifically tubulin proteins) to achieve dissipative self-assembly to mimic a biological function in vitro, and 2) using artificial building blocks to achieve dissipative self-assembly with molecules that have been synthesized in our laboratory. Both systems are in fact so-called supramolecular polymers, that is, long chains consisting of smaller building blocks that stick together using weak and reversible interactions. Such supramolecular polymers have been studied widely in the field, but mostly at (or close to) the thermodynamic equilibrium (note: a living system at thermodynamic equilibrium is dead). Instead, nature uses an input of energy (for example food or air) to keep its supramolecular polymer systems away from the thermodynamic equilibrium. Here we try to learn from nature (project 1) and secondly, try to build an artificial system using synthesized molecules.

So far, we have developed new tools to keep supramolecular polymers out of equilibrium. To this end, we have made flow devices that allow “food” (in the form of GTP, guanosine triphosphate) to be added to the tubulin assembling protein continuously. We used 3D printing and metal casting (borrowed from the jewelry in industry) to develop microfluidic chips where we can image the tubulin supramolecular polymers (i.e., microtubules), and at the same time control the addition of food (GTP) and remove the waste products (i.e., GDP, guanosine diphosphate, and inorganic phosphate). To understand the thermodynamic properties of this system better we are developing a continuous flow calorimeter, which is not commercially available. The second generation prototype (currently under construction) will allow us to measure the heat produced in so-called nonequilibrium steady-states. The latter is of fundamental importance to understand biological function arising from supramolecular polymers (such as microtubules or actin filaments). To keep our artificial supramolecular polymers (project 2) out of equilibrium we use magnetic fields (2 Tesla). We developed a customized light scattering setup, where we can determine the size of the polymers while exposing them to the magnetic field (or shortly thereafter).

The larger goal of these two ongoing projects is to understand and mimic how nature used non-equilibrium conditions to control the behavior of supramolecular structures, which is largely unexplored in the field of supramolecular chemistry. One of the possible practical outcomes could be the commercialization of our continuous flow calorimeter, which could be used to study many other systems.

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