CAREER: Designing a Synthetic Nucleolus for Cell Free Biocatalysis

Non-Technical Abstract:

This research will develop new biomaterials incorporating enzymes. Enzymes are functional proteins that act as a catalyst for chemical reactions in nature. They have the potential to make fuels, pharmaceuticals, and fine chemicals in efficient, selective, and ecofriendly ways compared to current industrial methods based on petroleum.

The full power of enzymes has yet to be unleashed on chemical manufacturing because in nature enzymes work with other enzymes in complex networks, under mild conditions, that are incompatible with industrial processes. This proposal investigates the fundamental science of how new biomaterials can be used to create useful multi-enzyme systems like those in nature.

In addition, biomaterials education of K-12, undergraduate, and graduate students is integrated throughout this proposal through the development of bilingual (English/Spanish) experiences and content aimed at increasing Hispanic participation in science, technology, engineering, and math careers. Technical Abstract:

Enzymes can synthesize chemical products in efficient, selective, and ecofriendly ways compared to the current dominant method: petroleum-based synthetic chemistry. However, the full power of biocatalysis has yet to be unleashed due to inadequate methods of integrating multienzyme pathways outside of cells into chemical manufacturing. Nature has efficient strategies to control multienzyme reactions using spatiotemporal regulation.

For instance, intracellular structures like the nucleolus, which are liquid droplets consisting of multiple phases, confine different enzymes in each phase to assemble the ribosome. The nucleolus is able to function in the complex interior of the cell by sequestering the necessary components and excluding others. In addition, the nucleolus can then dynamically assemble and disassemble when needed in different stages of the cell cycle.

If the structure of the nucleolus can be mimicked and used to perform multienzyme reactions outside of a cellular environment, this would transform chemical manufacturing by providing higher yields and reducing cost and waste. This proposal investigates the fundamental biomaterials science required to recreate the structure and mimic the function of the nucleolus.

A library of peptide based complex coacervates, that form liquid droplets similar to the nucleolus, will be designed with varying interfacial tensions and encapsulation selectivity. This library will be used to evaluate the conditions needed to achieve stable multiphase coacervates and measure diffusion of additives within and between the phases. Finally, the function of different synthetic nucleoli will be tested using an enzyme cascade reaction and correlated to the material properties of the phases.

Throughout this proposal the science of "biomaterials phase separation" will be used to increase the participation of Hispanic students in STEM careers. Key to this effort is the development of an experiential and bilingual (English/Spanish) summer program for ages 10-13 geared to improve science communication at home, a key indicator of choosing STEM careers.

This program is paired with a bilingual social media campaign introducing "biomaterials phase separation" science to teenagers and coursework and laboratory experiences for undergraduates and graduate students.

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.