Related Experiment Video
Updated: Apr 27, 2026
Lighting Up the Pathways to Caspase Activation Using Bimolecular Fluorescence Complementation
Published on: March 5, 2018
Single-molecule sensing of caspase activation in live cells via plasmon coupling nanotechnology
Cheryl Tajon1, Young-Wook Jun2, Charles S Craik1
1Department of Pharmaceutical Chemistry, University of California, San Francisco, California, USA; Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, California, USA.
Abstract:
Apoptotic caspases execute programmed cell death, where low levels of caspase activity are linked to cancer (Kasibhatla & Tseng, 2003). Chemotherapies utilize induction of apoptosis as a key mechanism for cancer treatment, where caspase-3 is a major player involved in dismantling these aberrant cells. The ability to sensitively measure the initial caspase-3 cleavage events during apoptosis is important for understanding the initiation of this complex cellular process; however, current ensemble methods are not sensitive enough to measure single cleavage events in cells. To overcome this, we describe a procedure to develop peptide-linked gold nanoparticles that have unique optical properties and can serve as beacons to visualize the apoptotic drug response in cancer cells at the single-molecule level. By thorough analyses of their trajectories, one can reveal early-stage caspase-3 activation in live cells continuously and with no ambiguity.
Insights
Researchers developed novel peptide-linked gold nanoparticles to detect early caspase-3 activation in cancer cells. This breakthrough enables single-molecule visualization of apoptosis, improving cancer drug response monitoring.
Area of Science:
- Biochemistry
- Nanotechnology
- Cancer Research
Background:
- Apoptotic caspases are crucial for programmed cell death, and their dysregulation is linked to cancer.
- Caspase-3 is a key enzyme in chemotherapy-induced apoptosis, essential for eliminating cancer cells.
- Current methods lack the sensitivity to detect early, single caspase-3 cleavage events during apoptosis.
Purpose of the Study:
- To develop a sensitive method for visualizing early caspase-3 activation at the single-molecule level.
- To create peptide-linked gold nanoparticles with unique optical properties for apoptosis detection.
- To enable continuous, unambiguous monitoring of early-stage caspase-3 activation in live cancer cells.
Main Methods:
- Synthesized peptide-linked gold nanoparticles with specific optical properties.
- Utilized nanoparticles as beacons to visualize apoptotic drug response in cancer cells.
- Analyzed nanoparticle trajectories to detect single-molecule cleavage events.
Main Results:
- Developed gold nanoparticles capable of single-molecule detection of caspase-3 activity.
- Demonstrated visualization of early-stage caspase-3 activation in live cancer cells.
- Established a method for continuous and unambiguous monitoring of apoptosis initiation.
Conclusions:
- Peptide-linked gold nanoparticles offer a highly sensitive platform for studying apoptosis.
- This technology allows for real-time, single-molecule analysis of caspase-3 activation.
- The findings have implications for understanding cancer cell death and evaluating cancer therapies.
