# Interrogating the Haloferryl State of Iron(II)- and 2-Oxoglutarate-Dependent Halogenases through Mimicry and Active Site Modifications

> **NIH NIH F32** · PENNSYLVANIA STATE UNIVERSITY, THE · 2022 · $69,802

## Abstract

Project Summary
 Within Nature, key cellular processes – e.g. transcription, reproduction, and production of small molecule
metabolites - are carried out by enzymes containing non-heme iron cofactors. One class of these enzymes, the
Fe- and 2-oxogluterate- (2OG) dependent enzymes, are well-known for their versatility and ability to catalyze
different reactions within the same active site. This project aims to investigate the reactivity of a less
characterized subclass of Fe/2OG-dependent enzymes-the halogenases. The halogenases, like all known
Fe/2OG enzymes, utilize the common oxidizing ferryl intermediate, [FeIV=O]2+, to abstract a hydrogen atom from
the substrate and then insert a halide ion or exogenous anion. The orientation of the halide ion relative to the
ferryl intermediate and substrate is not well understood; however, this orientation has been implicated in the
outcome of the product. Recent work has indicated that the unstable ferryl intermediate can be structurally
mimicked by the stable vanadyl ion, [VIV≡O]2+. When this is incorporated into a hydroxylase Fe/2OG enzyme
active site, it allows for prolonged study. Incorporation of vanadyl in Fe/2OG halogenases offers a unique
opportunity to investigate the position of the substrate in relation to the metal and the cosubstrates involved in
reactivity. These studies will utilize advanced spectroscopic methods alongside integration of non-canonical
amino acids within the halogenase active site. Unnatural amino acid coordination to the metal site may provide
the ability to alter, and potentially tune, reactivity and product formation in the native Fe/2OG-bound moiety, while
introducing unique spectroscopic comparisons in the vanadyl-bound complex. The knowledge gained by this
proposal will lead to a fundamental understanding of factors that dictate the reaction outcome within these
halogenase active sites and how to harness selective reactivity for drug design and synthesis.

## Key facts

- **NIH application ID:** 10643571
- **Project number:** 3F32GM136156-02S1
- **Recipient organization:** PENNSYLVANIA STATE UNIVERSITY, THE
- **Principal Investigator:** Jeffrey Worthington Slater
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $69,802
- **Award type:** 3
- **Project period:** 2020-08-01 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10643571

## Citation

> US National Institutes of Health, RePORTER application 10643571, Interrogating the Haloferryl State of Iron(II)- and 2-Oxoglutarate-Dependent Halogenases through Mimicry and Active Site Modifications (3F32GM136156-02S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10643571. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*