Related Experiment Video
Updated: Jul 19, 2026
11:42
Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
DNA-duplexes containing abasic sites: correlation between thermostability and acoustic wave properties
1Laboratory of Biophysics, Faculty of Mathematics, Physics and Computer Science, Comenius University, Mlynská dolina F1, 842 48 Bratislava, Slovak Republic.
The Analyst
|September 28, 2006
Summary
This study models DNA damage using abasic sites, finding that their number and location significantly destabilize DNA duplexes. Acoustic wave detection accurately measured these destabilization effects, correlating with solution-based thermal stability.
Area of Science:
- Biochemistry
- Molecular Biology
- Nanotechnology
Background:
- Apurinic/apyrimidinic (abasic) sites are common toxic DNA lesions.
- These lesions lack a nucleobase and can disrupt DNA structure and function.
- Modeling abasic sites is crucial for understanding DNA damage and repair.
Purpose of the Study:
- To synthesize a structural analog of an abasic site for use as a damaged nucleic acid probe.
- To investigate the impact of abasic sites on DNA duplex stability using acoustic wave detection.
- To correlate surface-based measurements with solution-based DNA thermal stability.
Main Methods:
- Synthesis of a 2-(hydroxymethyl) tetrahydrofuranyl residue as an abasic site analog.
- Preparation of oligodeoxyribonucleotides with varying numbers of abasic sites.
- Hybridization of modified oligonucleotides to complementary sequences immobilized on a gold surface via neutravidin-biotin interaction.
- Detection using a thickness shear mode acoustic wave detector to measure changes in electrical impedance (Deltafs and Rm).
- UV-monitored melting curves to assess DNA duplex thermostability in solution.
Main Results:
- The acoustic wave method successfully detected changes associated with DNA duplex formation.
- Measured frequency and resistance changes correlated well with DNA duplexes' thermostability in solution.
- Both the number and localization of abasic sites influenced duplex destabilization.
- Three abasic sites completely destabilized a 19 base pair DNA duplex.
Conclusions:
- The synthesized abasic site analog serves as an effective model for damaged nucleic acid studies.
- Thickness shear mode acoustic wave sensing provides a reliable method for evaluating DNA duplex stability.
- Abasic site presence and distribution are critical determinants of DNA structural integrity.
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...
02:27DNA Base Pairing
Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule,
01:30Spontaneous and Induced Mutations
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
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...
02:04Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
01:49Conserved Binding Sites
Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...