Research Seminar
Coumarin–peptide derivatives are ideal for the design of switchable self-assembling biomaterials with applications in nanoelectronics. We probe the role of hydrophobicity and aromaticity in the stability and pH-switchability of (RXDX)4 fibers using molecular dynamic simulations. Furthermore, we study the effect of mutating a single hydrophobic residue in the (RXDX)4 to an unnatural coumarin amino acid. Using a variety of peptide and coumarin order metrics, we show the hydrophobicity of the peptide sequence changes fiber stability and pH-switchability in both (RXDX)4 and coumarin-(RXDX)4 fibers. Increasing hydrophobicity leads to increased fiber stability at both neutral and acidic pH and a reduction in pH switchability of (RXDX)4 fibers. These trends are consistent for (RXDX)4-coumarin fibers with subtle differences due to the addition of coumarin. Our work suggests that we can use hydrophobicity to tune the pH-switchability of the optical properties of coumarin-(RXDX)4 fibers.
