UNS: Computational Design of Generic Underwater Adhesives based on Conjugating DOPA-Containing Polymers and Amyloid-Forming Peptides

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#1512058Hall, Carol K. Generic adhesives capable of sticking to surfaces in water or in high moisture conditions are in demand for applications ranging from marine coatings to medical devices to underwater sensors. One way to develop such adhesives is to learn from nature. Analysis of the adhesive substances employed by mussels, barnacles, algae and yeasts reveals two common factors that seem to contribute to their ability to attach to a wide range of surfaces in water: 3, 4-dihydroxyphenylalanine (DOPA) and amyloid-forming peptides. A new class of generic underwater adhesives will be developed by combining synthetic DOPA-containing polymers and amyloid-forming peptides. Synthetic materials will be deployed, instead of the naturally-occurring proteins favored by other investigators, because they should be easier to tailor and to produce in large scale. A computationally-driven program of research will be conducted to better the understanding of how the peptide sequences and DOPA-containing polymers in a peptide-polymer conjugate can be engineered to function synergistically, thereby providing superior adhesion to surfaces in water. Atomistic and coarse-grained molecular simulations will be used to develop a set of molecular-level principles that can guide the design of DOPA-peptide conjugates. Such materials, which are inspired by naturally-occurring materials including mussels and barnacles, are expected to form the basis of a new generation of underwater adhesives capable of binding to a wide range of surfaces. Five short peptide sequences taken from the amyloid forming regions of the glues employed by yeast cells have been identified as good starting sequences. Four surfaces will be considered: graphite, graphite coated with OH groups, gold, and titanium oxide. The specific aims of this project are to: 1) identify the roles played by each amino-acid residue on naturally-derived peptides in forming amyloid structure; 2) develop a set of principles for designing polymer-peptide conjugates such that the peptides can form amyloid structures without associating with the polymers; and 3) investigate the behavior of conjugates near four model surfaces to assess their ability to attach nonspecifically in water. The DOPA-peptide conjugates that show the most promise will be synthesized by an experimentalist collaborator, and tested to see if they form amyloid structures and if they adhere strongly to the four surfaces. The proposed project could impact research in the areas of interfacial phenomena, sensing, coating, surface modification and drug delivery where material adherence to surfaces in water is critical. The computational design strategy, which draws initial inspiration from natural products and then iterates back and forth between atomistic and coarse-grained simulations to home in on promising molecular architectures, could point the way to the systematic design and discovery of other new materials that are tailored for specific applications. In addition to training a Ph.D. student, research and education will be fostered by: (1) using the computational design of the new materials as the basis for examples developed for the PI's undergraduate chemical engineering thermodynamics course, (2) creating a power-point presentation describing the basics of computational materials design and distributing via the web, and (3) making a video presentation targeted for general audiences that shows how molecular-level computer simulation can be used to design materials with special functionality. The PI will continue her considerable, but informal, nationwide activities to broaden the opportunities for women in STEM fields and will introduce a brown bag lunch series for women graduate students and postdocs in her department at NCSU to discuss topics of common interest.