# O2-Reactivity in De Novo Designed Mononuclear, Non-Heme Fe Proteins

> **NIH NIH F32** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2020 · $64,554

## Abstract

Project Summary/Abstract:
Metalloenzymes perform chemical transformations with rates and selectivities that remain the
envy of synthetic chemists. By definition these transformations utilize earth-abundant transition
metals and environmentally friendly reagents. Furthermore, while some metalloenzymes utilize
specialized cofactors, many are able to achieve these transformations using the relatively limited
natural ligand set provided by the amino acids. Indeed, in many cases a single coordination motif
is used to promote a variety of mechanistically distinct transformations providing evidence for the
important of the secondary and tertiary structure of the protein environment for dictating reaction
mechanism. One approach to understanding the structure-function principles is to de novo design
metalloenzymes from scratch. Herein we exploit de novo protein design to allow us to
systematically alter the local environment around a biologically important, ambiphilic reaction
intermediate, the ferric superoxo. We then seek to utilize this understanding and the newfound
ability to design specific small molecule binding proteins to explore physiologically important C–
H activation reactions at a mononuclear, non-heme Fe center. C–H activation reactions are of
particular interest from a structure-function perspective because their success has been shown
to be highly dependent on substrate positioning, thereby providing a sensitive test of our ability to
de novo design binding pockets. Improving our ability to design controlled binding pockets would
open the possibility for many applications of de novo proteins. The proposed studies will primarily
be achieved using optical spectroscopy to characterize the electronic structure and
thermochemistry of the different species. These studies will be complemented by structural
information derived from multinuclear NMR spectroscopy and X-ray crystallography. The results
would represent a breakthrough in protein design with implications for fundamental understanding
of how metalloproteins utilize simple ligand sets to generate and harness reactive intermediates
for achieving chemically challenging transformations.

## Key facts

- **NIH application ID:** 10067864
- **Project number:** 1F32GM139379-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Matthew Chalkley
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $64,554
- **Award type:** 1
- **Project period:** 2020-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10067864

## Citation

> US National Institutes of Health, RePORTER application 10067864, O2-Reactivity in De Novo Designed Mononuclear, Non-Heme Fe Proteins (1F32GM139379-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10067864. Licensed CC0.

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