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A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
Screening the sequence selectivity of DNA-binding molecules using a gold nanoparticle-based colorimetric approach
Sarah J Hurst1, Min Su Han, Abigail K R Lytton-Jean
1Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA.
Analytical Chemistry
|August 19, 2007
Summary
Researchers developed a novel gold nanoparticle assay to screen DNA-binding molecules. This colorimetric method measures changes in DNA-nanoparticle melting temperature to determine sequence selectivity, aiding drug discovery.
Area of Science:
- Biochemistry
- Nanotechnology
- Molecular Biology
Background:
- Assessing sequence selectivity of DNA-binding molecules is crucial for drug discovery.
- Existing methods often require complex instrumentation and are not high-throughput.
Purpose of the Study:
- To develop a novel, high-throughput, colorimetric assay for screening DNA-binding molecule sequence selectivity.
- To utilize gold nanoparticle (Au NP) aggregation and melting behavior as a readout for DNA-binding affinity.
Main Methods:
- Developed a competition assay using DNA-functionalized Au NP aggregates.
- Measured changes in melting temperature (Tm) of Au NP aggregates in response to DNA-binding molecules and hairpin DNA sequences.
- Evaluated the assay's performance with known AT-specific, GC-specific, and non-specific DNA-binding molecules.
Main Results:
- The assay demonstrated sensitivity to the sequence selectivity of different DNA-binding molecules.
- Confirmed known binding trends for AT-specific (4',6-diamidino-2-phenylindone), GC-specific (chromomycin A), and non-specific (ethidium bromide) binders.
- The assay accurately assessed selectivity across various hairpin DNA sequences without complex instrumentation.
Conclusions:
- The novel Au NP-based colorimetric assay is effective for screening DNA-binding molecule sequence selectivity.
- This method offers a high-throughput, accessible approach for evaluating potential DNA-targeting drug candidates.
- The assay's sensitivity to melting temperature changes provides a reliable measure of relative DNA-binding affinity.
