Related Experiment Video
Updated: Oct 4, 2025
OaAEP1-Mediated Enzymatic Synthesis and Immobilization of Polymerized Protein for Single-Molecule Force Spectroscopy
Published on: February 5, 2020
Solid-Phase Synthesis and Application of a Clickable Version of Epoxomicin for Proteasome Activity Analysis
Andres F Salazar-Chaparro1, Saayak Halder1, Marianne E Maresh1
1Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, 47907, USA.
Abstract:
Degradation of proteins by the proteasome is an essential cellular process and one that many wish to study in a variety of disease types. There are commercially available probes that can monitor proteasome activity in cells, but they typically contain common fluorophores that limit their simultaneous use with other activity-based probes. In order to exchange the fluorophore or incorporate an enrichment tag, the proteasome probe likely has to be synthesized which can be cumbersome. Here, we describe a simple synthetic procedure that only requires one purification step to generate epoxomicin, a selective proteasome inhibitor, with a terminal alkyne. Through a copper-catalyzed cycloaddition, any moiety containing an azide can be incorporated into the probe. Many fluorophores are commercially available that contain an azide that can be "clicked", allowing this proteasome activity probe to be included into already established assays to monitor both proteasome activity and other cellular activities of interest.
Insights
Researchers developed a new method to create a versatile proteasome activity probe. This allows for easier monitoring of proteasome function and other cellular processes simultaneously in disease research.
Area of Science:
- Biochemistry
- Cell Biology
- Chemical Biology
Background:
- Proteasome-mediated protein degradation is crucial for cellular function and implicated in various diseases.
- Existing proteasome activity probes often use common fluorophores, hindering simultaneous multi-analyte detection.
- Modifying these probes typically requires complex synthesis and purification.
Purpose of the Study:
- To develop a simplified synthetic route for a versatile proteasome inhibitor probe.
- To enable the facile incorporation of various detection or enrichment moieties.
- To facilitate simultaneous monitoring of proteasome activity alongside other cellular processes.
Main Methods:
- A streamlined synthesis of epoxomicin, a proteasome inhibitor, yielding a terminal alkyne functional group.
- Utilizing copper-catalyzed cycloaddition (click chemistry) for azide-containing moiety conjugation.
- Demonstrating the probe's compatibility with existing assays for multiplexed analysis.
Main Results:
- A novel, easily synthesized epoxomicin derivative with a terminal alkyne was generated in one purification step.
- The alkyne handle allows for straightforward attachment of azide-containing molecules, such as fluorophores.
- The modified probe can be integrated into established assays for simultaneous proteasome activity and other cellular activity measurements.
Conclusions:
- This work presents a simplified and adaptable method for creating functionalized proteasome activity probes.
- The developed probe enhances the capability for multiplexed cellular activity monitoring in disease research.
- This approach offers a valuable tool for studying complex biological systems and disease mechanisms.
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
