Stability of human telomere quadruplexes at high DNA concentrations
Jazyk angličtina Země Spojené státy americké Médium print
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
24037480
DOI
10.1002/bip.22400
Knihovny.cz E-zdroje
- Klíčová slova
- DNA concentration, circular dichroism, folding topology, quadruplex, thermal and thermodynamic stability,
- MeSH
- cirkulární dichroismus MeSH
- denzitometrie MeSH
- DNA chemie MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- entropie MeSH
- G-kvadruplexy * MeSH
- lidé MeSH
- mikroskopie atomárních sil MeSH
- spektrofotometrie ultrafialová MeSH
- telomery chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA MeSH
For mimicking macromolecular crowding of DNA quadruplexes, various crowding agents have been used, typically PEG, with quadruplexes of micromolar strand concentrations. Thermal and thermodynamic stabilities of these quadruplexes increased with the concentration of the agents, the rise depended on the crowder used. A different phenomenon was observed, and is presented in this article, when the crowder was the quadruplex itself. With DNA strand concentrations ranging from 3 µM to 9 mM, the thermostability did not change up to ∼2 mM, above which it increased, indicating that the unfolding quadruplex units were not monomolecular above ∼2 mM. The results are explained by self-association of the G-quadruplexes above this concentration. The ΔG(°) 37 values, evaluated only below 2 mM, did not become more negative, as with the non-DNA crowders, instead, slightly increased. Folding topology changed from antiparallel to hybrid above 2 mM, and then to parallel quadruplexes at high, 6-9 mM strand concentrations. In this range, the concentration of the DNA phosphate anions approached the concentration of the K(+) counterions used. Volume exclusion is assumed to promote the topological changes of quadruplexes toward the parallel, and the decreased screening of anions could affect their stability.
Citace poskytuje Crossref.org
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