Related Experiment Video
Updated: May 16, 2026
06:59
Nanomanipulation of Single RNA Molecules by Optical Tweezers
Published on: August 20, 2014
DNA hairpin stabilization on a hydrophobic surface
Mark Kastantin1, Daniel K Schwartz
1Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA.
Small (Weinheim an Der Bergstrasse, Germany)
|November 28, 2012
Summary
Hydrophobic surfaces promote DNA hairpin formation more effectively than hydrophilic ones, contrary to expectations. This finding suggests hydrophobic coatings are better for DNA hybridization applications in nanotechnology.
Area of Science:
- Biophysics
- Surface Science
- Nanotechnology
Background:
- DNA hybridization near surfaces is crucial for nanoarrays, superlattices, and biosensors.
- Solid surfaces influence DNA hybridization dynamics compared to bulk solution.
Purpose of the Study:
- Investigate DNA hairpin-coil conformational transitions near hydrophilic oligo(ethylene glycol) (OEG) and hydrophobic trimethylsilane (TMS) surfaces.
- Understand surface interactions with individual DNA bases during hybridization.
Main Methods:
- Employed single-molecule methods to observe DNA hairpin-coil transitions.
- Simultaneously measured molecular surface diffusion.
- Analyzed over 35,000 molecular trajectories on each surface type.
Main Results:
- DNA hairpin unfolding slowed, while folding rates increased on TMS surfaces compared to OEG.
- Despite stronger attractions between TMS and unpaired nucleobases, hydrophobic surfaces favored hairpin formation.
- Observed near-complete hairpin formation on TMS and significant unfolding on OEG.
Conclusions:
- Hydrophobic surface coatings are preferable for nanotechnology applications requiring DNA hybridization near surfaces.
- Surface properties significantly impact DNA conformational dynamics and hybridization efficiency.
Related Concept Videos
01:03Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
02:37Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
00:55DNA Helicases
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
01:02The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
01:25Nucleic Acid Structure
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...
DNA Structure
DNA has a double-helix structure. The...
01:53RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...