# From Fundamental Studies of Metalloproteins to Practical Applications

> **NIH NIH R15** · SYRACUSE UNIVERSITY · 2022 · $63,370

## Abstract

Metalloenzymes are capable of efficiently tuning the properties of a metal ion to catalyze very difficult chemical
transformations. Yet the determinants of what guides the evolution of protein function still remain not fully
understood. This lack of understanding of the subtle detail of interactions that determine enzymatic function limits
our ability to rationally design catalysts. We will test why the same family of enzymes uses different
metallocofactors. Metalloenzyme NrdF belongs to a class of ribonucleotide reductases (RNR), essential
enzymes found in all organisms to catalyze the conversion of nucleotides to deoxynucleotides. RNRs rely on
metals to oxidize a conserved cysteine in the active site into a thiyl radical, which then initiates nucleotide
reduction. Several different classes of RNRs have been identified in various organisms and, interestingly, despite
a remarkable conservation of the overall catalytic pathway, the enzyme can utilize different metals to achieve it.
We have recently shown that dimanganese center in class Ib RNRs of pathogenic organisms performs the same
task as the diiron center in humans. Moreover, other class I RNR enzymes utilize diiron and mixed iron-
manganese centers for function. The molecular and biological determinants of this metal preference still
remain unknown and present a major unanswered question in the field. To address this question, we
devised three specific aims. Aim 1. Elucidation of the origins of specific metalation in RNR. Using class Ib
RNR from Streptococcus sanguinis (Ss) we will address the fundamental question of how correct metalation of
enzymes is controlled. Aim 2. Design of functional RNR models. We will use a stable and simple protein model
of RNR (DFsc) to bind various metal ions and generate catalysts for practically useful reactions. This aim will
give simple, inexpensive and biocompatible protein catalysts for redox transformations and pesticide/chemical
weapons remediation in the environment, that could be easily handled in the applied setting. Aim 3. Structural
characterization of metalloproteins. Here we will test how metal ions influence the structure of the protein.
The work proposed in this aim will validate and correlate the studies on the natural enzymes.

## Key facts

- **NIH application ID:** 10580467
- **Project number:** 1R15GM148939-01
- **Recipient organization:** SYRACUSE UNIVERSITY
- **Principal Investigator:** OLGA MAKHLYNETS
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $63,370
- **Award type:** 1
- **Project period:** 2022-09-15 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10580467

## Citation

> US National Institutes of Health, RePORTER application 10580467, From Fundamental Studies of Metalloproteins to Practical Applications (1R15GM148939-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10580467. Licensed CC0.

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