Effects of Central Loop Length and Metal Ions on the Thermal Stability of G-Quadruplexes.
Molecules
; 24(10)2019 May 15.
Article
em En
| MEDLINE
| ID: mdl-31096553
ABSTRACT
The central loop of G-quadruplex molecular beacons is a key element to sense target DNA or RNA sequences. In this study, circular dichroism spectroscopy (CD), thermal difference spectrum (TDS), non-denatured non-denaturing gel electrophoresis, and thermal stability analysis were used to investigate the effect of the central loop length on G-quadruplex features. Two series of G-quadruplexes, AG3TTAG3-(TTA)n-G3TTAG3T (n = 1-8) (named TTA series) and AG3TTTG3-(TTA)n-G3TTTG3T (n = 1-8) (named TTT series) were examined in K+ and Na+ solutions, respectively. CD and TDS spectral data indicated that TTA series adopted an antiparallel G-quadruplex structure in Na+ solution and a hybrid G-quadruplex structure in K+ solution respectively. TTT series exhibited a hybrid G-quadruplex structure in both Na+ and K+ solutions. UV melting curves indicated that the stability of G-quadruplex in both series was reduced by the elongation of central loop. Thermal stability analysis concluded that the G-quadruplex destabilization with long central loop is an entropy-driven process due to more flexible and longer central loops.
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MEDLINE
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Termodinâmica
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DNA
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Quadruplex G
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Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article