# Activity-based protein profiling of the human rhomboid proteases for inhibitor discovery and enzyme characterization

> **NIH NIH R15** · OBERLIN COLLEGE · 2022 · $372,264

## Abstract

Hydrolases, proteins that cleave covalent bonds using water, represent one of the largest classes of enzymes
in the human body and play essential roles in numerous physiological pathways ranging from digestion to
nervous system signaling. Despite the prevalence and importance of this enzyme class, the biological functions
of many hydrolases remain poorly characterized. Among these less studied members, rhomboid intramembrane
proteases (RIPs), which perform hydrolysis chemistry within the hydrophobic environment of biological
membranes, are of particular interest. Mutation and dysregulation of these enzymes in neurodegenerative
diseases and multiple types of cancer motivates the development of an enhanced understanding of their
physiological roles and an investigation of their potential to serve as therapeutic targets; however, methods to
conduct these studies are currently lacking. Activity-based protein profiling (ABPP) technology, in which active
site-directed chemical probes are used to detect enzyme activity, has facilitated the characterization of many
serine hydrolases. As members of this superfamily of enzymes, RIPs represent promising candidates for study
by ABPP methods, which can then be leveraged to discover selective inhibitors and to characterize the active
proteoforms of these enzymes. This proposal aims to (1) develop optimized ABPP assays to monitor the activity
of each of the five human rhomboid proteases in complex biological samples, (2) generate and screen a library
of N-sulfonylated heterocycles as potential inhibitors for these enzymes, and (3) characterize proteolytic
processing of the ER-localized RIP RHBDL4 and the impact of processing on enzymatic activity. These studies
will empower efforts to investigate the physiological roles of the human RIPs and their potential as therapeutic
targets. Further, the proposed project will provide an opportunity to train Oberlin undergraduate researchers in
contemporary chemical biology methods that incorporate techniques from synthetic chemistry, biochemistry, and
molecular biology. Research students at Oberlin will learn theory and advanced laboratory skills not otherwise
covered in an undergraduate classroom setting while developing their ability to analyze and present scientific
data. Collectively, these activities will enrich the research environment at Oberlin College and help prepare the
next generation of researchers in interdisciplinary molecular science.

## Key facts

- **NIH application ID:** 10437985
- **Project number:** 1R15GM146210-01
- **Recipient organization:** OBERLIN COLLEGE
- **Principal Investigator:** William Hazen Parsons
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $372,264
- **Award type:** 1
- **Project period:** 2022-05-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10437985

## Citation

> US National Institutes of Health, RePORTER application 10437985, Activity-based protein profiling of the human rhomboid proteases for inhibitor discovery and enzyme characterization (1R15GM146210-01). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10437985. Licensed CC0.

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