Supercharged enzyme-polymer surfactant bioblocks for the preparation of organophosphate decontaminating materials

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Since their widespread application as pesticides in rural areas of developing countries, it is estimated that approximately 3 million people worldwide are poisoned by organophosphates (OPs) every year. OPs have also been used in chemical warfare agent formulations, in incidents including the Ghouta Sarin Attack in Syria, 2013, and the Japanese subway attacks in 1994 and 1995. According to a French intelligence assessment published in September 2013, stockpiles in Syria alone include several hundreds of tonnes of sarin and several tens of tonnes of VX. Accordingly, this research proposal describes the application of synthetic biology for the rational design of versatile supercharged enzyme-polymer surfactant building blocks (bioblocks) for the preparation of organophosphate decontaminating materials that span all three phases of matter. Here, the surfaces of synthetic supercharged variants of the organophosphate-degrading enzyme organophosphate hydrolase (OPH) will be radically re-engineered to produce adhesive enzyme-polymer melts, stable bioaerosols, and hierarchically assembled solid membranes.The versatility in this new methodology is highly dependent on the ability to manipulate protein-protein interactions through the construction of an electrostatically-assembled polymer surfactant corona at the surface of a supercharged enzyme, which is based on the synthetic methodology recently pioneered by AWP. The approach involves the reengineering of a protein surface in two key steps: (i) amplification of the positive charge density on the protein surface, followed by (ii) electrostatic coupling of anionic polymer surfactant chains to the cationic sites on the protein surface. Significantly, the resulting surface-bound corona of polymer surfactant molecules increases the range of the attractive intermolecular protein-protein interactions, which in turn allows the particle motions required for melt formation under anhydrous conditions. Alternatively, the hydrophilic-lipophilic balance (HLB) of the corona can be tuned to either provide organic solvent compatibility for aerosol generation or to promote surfactant mediated self-assembly to produce nanoporous solids. Accordingly, the global aim of this research proposal is the rational design and synthesis of the organophosphate-degrading enzyme-polymer surfactant bioblocks that can be used for the preparation of these three classes of organophosphate decontaminating materials. The research program will be implemented sequentially across four primary research objectives: - In silico inspired design, expression and purification of a supercharged organophosphate hydrolase (scOPH) library - The synthesis of high-density scOPH-polymer melts - Active bioaerosol generation using organic solvent compatibility - Surfactant-mediated assembly of scOPH to give porous solids with recyclable catalytic activitiesThe research programme describes a scientific approach that combines in-house techniques for synthetic biology, biophysics and materials science, as well as techniques available at large-scale facilities. As there is a strong application focus in the programme, the new methodology describes the development of recombinant supercharged enzymes, which will be optimised for maximum catalytic performance. In conclusion, the development of a library of OP-degrading enzyme-polymer surfactant materials that can operate in all three phases represents a near-future platform technology that could be readily exploited for a multitude of new defence applications, including disbondable coating for military hardware or personnel, bioaerosol-based countermeasures for OP contaminated confined airspaces or for inhalation treatments, and high efficiency enzyme-based reactors for OP degradation/disposal.