CBE Seminar (Zoom): Polymorphism in Hierarchical Structures of Coiled-Coil Building Blocks

Abstract: Nature’s vast array of multifunctional proteins and peptides (short proteins) provides inspiration for synthetic stimuli-responsive nanomaterials. Both amino acid sequence and solution environment are key to dynamic protein folding/assembly into these multifunctional materials. Building on this foundation, novel pH sensitive peptide-based assemblies were designed and made. In this work, the assembly mechanism of a de novo designed peptide was probed through point mutations of the amino acid sequence and varying assembly solution conditions. The resulting structures are unprecedented hierarchical assemblies of α-helical coiled-coil hexamer building blocks. Buffer concentration and pH affect multi-scale aspects of supramolecular assembly, including peptide monomer secondary structure and interactions between hexamer building blocks. These higher order assembly interfaces are formed by hydrogen bonding networks between solvent-exposed lysines and glutamines, as analyzed by their cryo-electron microscopy structure. Here, the toolbox of self-assembling peptide sequences have been expanded to include new sequences and structures that can be used to create amino acid-based biomaterials that mimic the complexity and stimuli-responsiveness of their natural counterparts.

Bio: Adam Grosvirt-Dramen is a third-year Ph.D. student in the Department of Chemical and Biomolecular Engineering (CBE) working under Allon Hochbaum at UC Irvine. His work focuses on the intersection of nanotechnology, electrochemistry and biomaterials. Specifically, he designs peptide sequences that self-assemble into electrically conductive nanofibers as part of his work with the Center for Complex and Active Materials (CCAM), an NSF-funded Materials Research Science and Engineering Center (MRSEC). Before starting at UCI, Adam received his B.S. in chemical engineering from California State University, Long Beach.

Outside of the lab, Adam is the president of the CBE Graduate Student Association and a CBE graduate student mentor. He enjoys education and outreach as shown by his previous experience with the GSA at the Orange County Libraries and his current role devising remote outreach activities with MRSEC.