Collaborative Research: Water-responsive, Shape-shifting Supramolecular Protein Assemblies

Cuny City College, New York NY

Investigators

Abstract

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, the collaborative team consisting of Professors Jin Montclare (New York University), Xi Chen (CUNY - Advanced Science Research Center), and Raymond Tu (CUNY – City College) aim to create shape-shifting protein assemblies capable of responding to changes in relative humidity. The research is inspired by phenomena observed in nature such as how pinecones and wheat are able to dispense their seeds. The team will develop protein polymers that mimic those found in nature, explore their water-responsive motion, and explore the mechanical power generated by the material. The work will investigate: 1) the role of structure in such protein polymers; 2) the effects of protein polymer composition on water-responsiveness; and 3) how the nature of the molecular assembly leads to changes in their water-responsiveness. The ultimate goal is to achieve an understanding that will allow the team to design new water responsive protein polymers assemblies that can efficiently convert motion into usable energy. This may lead to the development of high-power moving components for widespread applications such as robotics, shape-morphing and energy harvesting devices. This highly interdisciplinary research, involving protein engineering, chemical engineering and materials science, will provide training for graduate, undergraduate, and high school students. In collaborative outreach efforts, the team will hold an annual “Biomimetic Technology” event that includes local New York City K-12 students and teachers to interact with state-of-the-art science to promote interest in science and increase public understanding of macromolecular science and engineering concepts. Evaporation-induced shape change has proven to be an efficient mechanism for the conversion of energy from water’s chemical potential to mechanical energy. Owing to this property, water responsive (WR) materials can swell and shrink in response to relative humidity (RH) changes, and recent studies have shown that biological WR materials can generate significantly higher energy actuation than all known muscles and actuators. Here, the team will focus on creating shape-shifting protein engineered assemblies that fundamentally integrate nano-scaled structural features that can hierarchically assemble and lead to macroscale function of energy conversion from the chemical potential of water to mechanical motion. The team will investigate how supramolecular self-assembly and phase separation influence the WR properties of protein engineered block-copolypeptides (BCPs). To achieve this the team aims to investigate: 1) the role of structure in the engineered BCPs; 2) the effects of the surface blocks on BCP water-responsiveness; and 3) the effect of supramolecular structure with water-responsiveness. This fundamental understanding is expected to help the researchers develop a set of parameters to inform the design of biological WR actuators with high energy and power densities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.