# Targeted molecular strategies for cellular investigation of metalloproteins

> **NIH NIH R35** · UNIVERSITY OF TEXAS AT AUSTIN · 2021 · $314,784

## Abstract

Project Summary/Abstract
Metals are essential micronutrients that are required for proper functioning of cells and organisms. As such,
cells have evolved a complex homeostatic machinery to control the distribution and speciation of metals, also
known as the metallome. Deviations from basic metallomic profiles are associated with multiple disease
processes, environmental metal contamination, and nutritional deficiencies and all have detrimental effects on
normal cellular function. The metallome is comprised of two main metal ion pools including the labile metal ion
pool in which metals are weakly bound to cellular ligands and the tightly-bound metal ion pool in which metals
are ligated to metalloproteins and other biomolecules with high affinity. Metalloproteins that constitute the
tightly-bound metal ion pool represent one third of the cellular proteome and within these proteins, metals have
diverse structural and catalytic functions. These metalloproteins can exist in several states including apo
(metal-free), holo (metal-bound), and mismetalated depending on the cellular context. While some information
is know about how the metalation state of selected metalloproteins is controlled (via metallochaperones and/or
action of specific metal transporters) the details of how the labile and metalloprotein-bound metal pools interact
in a cellular context as cells undergo dynamic changes is largely unknown and is a growing area of interest in
the metal homeostasis field. In order to probe these interactions and characterize how the pool of
metalloproteins changes in physiology and pathology, our goal is to develop a diverse chemical toolbox that
will enable imaging, identification, quantification, and molecular control of metalloprotein populations in cells,
tissues, and organisms. Our strategy centers on the use of precisely design molecular targeting groups that will
specifically interact with the metal sites of these proteins. These targeting groups are then modified with
functional tags including the following: 1) Fluorophores for live cell imaging and cell lysate protein analysis; 2)
Affinity probes for proteomics studies that enable trapping of metalloproteins in their native metallation state
and; 3) Photoresponsive groups for the selective control of specific metalloproteins and the development of
photopharmacophores. Initial studies have focused on zinc-dependent metalloenzymes including carbonic
anhydrases; however studies will be expanded to include a range of enzymes dependent on zinc (e.g. metallo-
β-lactamases, histone deacetylases, matrix metalloproteinases), iron (e.g. heme and non-heme) and copper
(e.g. superoxide dismutase). Tools will be applied in cellular models of metal dyshomeostasis and for profiling
metalloprotein pools in cancer cells and others and will be combined with additional metallomic analysis
including elemental analysis (inductively coupled plasma mass spectrometry, synchrotron-based x-ray
fluorescence microscopy) and ...

## Key facts

- **NIH application ID:** 10240581
- **Project number:** 5R35GM133612-03
- **Recipient organization:** UNIVERSITY OF TEXAS AT AUSTIN
- **Principal Investigator:** Emily L Que
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $314,784
- **Award type:** 5
- **Project period:** 2019-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10240581

## Citation

> US National Institutes of Health, RePORTER application 10240581, Targeted molecular strategies for cellular investigation of metalloproteins (5R35GM133612-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10240581. Licensed CC0.

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