# Defining the mechanistic determinants of catalytic bias in cofactor-based enzymatic oxidation-reduction reactions

> **NIH NIH R01** · WASHINGTON STATE UNIVERSITY · 2020 · $367,229

## Abstract

PROJECT SUMMARY
Enzymatic reactions comprise the basic building blocks essential to the biochemical processes of cellular
metabolism. While most enzymatic reactions are reversible, certain enzymes accelerate a reaction in one
direction significantly differently than the reverse direction. The mechanistic determinants of this phenomenon –
often referred to as “catalytic bias” – are generally unknown. Our long-term goal of this project is to identify the
fundamental principles adopted by redox enzymes (enzymes involved in oxidation-reduction reactions) that
provide molecular level control of the catalytic bias. In doing so, we will provide a greater fundamental
understanding of the factors that control metabolic processes in all life. Specifically, the objective of this proposal
is to delineate determinants that influence the directional reactivity of model Fe containing hydrogenases that
are structurally related but exhibit large differences in catalytic bias for the specific reversible hydrogen (H2)
oxidation reaction from electron and protons. The central hypothesis is that catalytic bias commonly in redox
enzymes results from the relative differential stabilization and destabilization of oxidation states of the respective
redox cofactors critical to determining the rate limiting step of the catalytic cycle. The rationale underlying the
proposal is that the implementation will result in defining mechanistic determinants of the proposed model
system. The proposed work will culminate in elucidating universal, mechanistic factors of catalytic bias that
govern a large number of, if not all, redox enzymes. The central hypothesis will be tested by pursuing three
specific aims that examine how 1) the reduction potential of the active site proximal accessory redox clusters; 2)
the characteristics of the active site cluster protein environment; and 3) the secondary coordination sphere
structural dynamics can control reactivity and catalytic bias in cofactor-based oxidation reduction catalysis. To
pursue these aims, we will employ an innovative strategy integrating biochemical, structural, spectroscopic, and
computational approaches on a unique, one-of-a-kind model hydrogenase platform. The proposed research is
significant, because it will delineate molecular determinants that influence the fine-tuning of redox cofactors
through the relative stabilization or destabilization of oxidation states to afford certain reactivity fundamental to
directing energy and matter in cells. The work will provide additional foundational resources in the form of a
blueprint for integrating multiple biophysical and computational approaches.

## Key facts

- **NIH application ID:** 10034848
- **Project number:** 1R01GM138592-01
- **Recipient organization:** WASHINGTON STATE UNIVERSITY
- **Principal Investigator:** JOHN W PETERS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $367,229
- **Award type:** 1
- **Project period:** 2020-09-15 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10034848

## Citation

> US National Institutes of Health, RePORTER application 10034848, Defining the mechanistic determinants of catalytic bias in cofactor-based enzymatic oxidation-reduction reactions (1R01GM138592-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10034848. Licensed CC0.

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