# Expanding the Metabolic Currencies of Life

> **NIH NIH R35** · UNIVERSITY OF CALIFORNIA-IRVINE · 2024 · $555,906

## Abstract

There is an unmet need to obtain natural product-derived medicines in a scalable and reliable manner.
Natural products are small molecules produced by biological systems, but often in low quantities. Synthetic
biology promises to move the biosynthetic pathways of these medicinal small molecules from their native
producers into heterologous hosts such as bacteria and yeast or into a bioreactor, so that large-scale, low-cost,
industrial processes can be developed to produce them. The long-term goal of my research program is to
address the ultimate challenge in chemical biosynthesis, namely to precisely control the flow of electrons,
carbon, and energy. Over the past five years, we have made substantial strides toward this goal, by
establishing unnatural electron currency which operates in parallel to Nature's universal cofactor. This design
is inspired by Nature: Catabolism and anabolism, two opposing metabolic systems responsible for breaking
down and building up cell components, respectively, are insulated from each other because they each have a
designated redox cofactor, NAD and NADP, respectively. We have demonstrated that our unnatural cofactor
can indeed precisely channel reducing power only to the desired pharmaceutical producing reactions inside the
cells while silencing all side-reactions, effectively insulting the biosynthetic pathway from the host's complex
native metabolism. Importantly, we have also developed universal, high-throughput, growth-based selection
platforms to readily obtain enzymes that can use the unnatural cofactor. Through these efforts, general
enzyme design principles also start to emerge which paves the way for our proposed work in the next five year.
Through the MIRA support, we will develop methods to drastically improve the efficiency of the unnatural
cofactor technology; make it easy to adopt by bioengineering community; bring this technology to bear on
difficult high-reward biosynthesis challenges; broaden the category of unnatural metabolic currencies from
electron- to carbon- and energy-carriers and distill translatable design principles; use this project as a vehicle
to include and promote diverse STEM researchers at K-12, undergraduate, graduate, and post graduate
stages. The proposed work is transformative because it directly targets life's universal metabolic infrastructure
and therefore can have extremely broad impacts in biomedicine and synthetic biology.

## Key facts

- **NIH application ID:** 10842995
- **Project number:** 1R35GM153401-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA-IRVINE
- **Principal Investigator:** Han Li
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $555,906
- **Award type:** 1
- **Project period:** 2024-06-01 → 2029-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10842995

## Citation

> US National Institutes of Health, RePORTER application 10842995, Expanding the Metabolic Currencies of Life (1R35GM153401-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10842995. Licensed CC0.

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