Home Neuroscience Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1
Neuroscience JoVE (Open Access) Citable · DOI

Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1

DOI: 10.3791/60045-v
What you'll learn
  • Set up flow cells and prepare surfaces for single-molecule FRET experiments
  • Perform two-color alternating excitation (ALEX) to determine dissociation constants
  • Analyze real-time smFRET data to obtain dwell time distributions during HJ resolution
  • Interpret single-molecule kinetics of GEN1-mediated Holliday junction cleavage
Protocol

Biopharma Insights Presented here is a protocol for performing single-molecule Förster resonance energy transfer to study HJ resolution. Two-color alternating excitation is used for determining the dissociation constants. Single-color time lapse smFRET is then applied in real-time cleavage assays to obtain the dwell time distribution prior to HJ resolution.

Difficulty
advanced
Total time
~4–6 hours per experiment (including surface preparation, data acquisition, and analysis)

Steps

1
Prepare flow cells for smFRET experiments

Assemble and prepare flow cells with appropriate surface chemistry for immobilizing Holliday junction substrates and proteins. This includes cleaning, coating, and functionalization of coverslips.

▶ 01:22
2
Conduct single-molecule FRET experiments

Perform smFRET measurements using single-color time-lapse imaging to monitor real-time Holliday junction cleavage by GEN1 and record dwell time distributions.

▶ 03:01
3
Analyze smFRET data for kinetic parameters

Process and analyze single-molecule FRET time series to extract dwell times, transition rates, and kinetic information related to HJ resolution.

▶ 06:25
4
Perform two-color alternating excitation (ALEX) experiments

Execute two-color ALEX-FRET measurements to determine dissociation constants and binding/unbinding kinetics of GEN1 with Holliday junction substrates.

▶ 07:10
5
Interpret representative results for HJ resolution

Review and interpret real-time smFRET data showing GEN1-catalyzed Holliday junction resolution, including temporal dynamics and cleavage mechanisms.

▶ 08:24
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