scholarly journals Short loop length and high thermal stability determine genomic instability induced by G‐quadruplex‐forming minisatellites

2015 ◽  
Vol 34 (12) ◽  
pp. 1718-1734 ◽  
Author(s):  
Aurèle Piazza ◽  
Michael Adrian ◽  
Frédéric Samazan ◽  
Brahim Heddi ◽  
Florian Hamon ◽  
...  
Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1863 ◽  
Author(s):  
Fengjin Hao ◽  
Yushu Ma ◽  
Yifu Guan

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.


Author(s):  
Sheng-Chieh Lin ◽  
Yu-Chieh Cheng ◽  
Man-Kit Leung ◽  
Jiun-Haw Lee ◽  
Tien-Lung Chiu

2011 ◽  
Vol 11 (5) ◽  
pp. 4639-4643 ◽  
Author(s):  
Chang-Hun Seok ◽  
Young-Il Park ◽  
Soo-Kang Kim ◽  
Ji-Hoon Lee ◽  
Jongwook Park

2019 ◽  
Vol 17 (1) ◽  
pp. 1080-1086
Author(s):  
Elżbieta Chmiel-Szukiewicz

AbstractSyntheses of oligoetherols with a 1,3-pyrimidine ring and boron atoms using 6-aminouracil, ethylene carbonate and boric acid has been proposed. The structure of the obtained products were determined by instrumental methods (IR, 1H-NMR and MALDI-ToF spectra). The physicochemical and thermal properties of oligoetherols were examined. The products were characterized by high thermal stability. Based on the tests performed, it was found that oligoetherols obtained from 6-aminouracil, boric acid and ethylene carbonate are suitable for the manufacturing of polyurethane foams with improved thermal stability and reduced flammability.


2021 ◽  
pp. 118234
Author(s):  
Yunlong Yang ◽  
Linyan Fu ◽  
Xuefei Ren ◽  
Yingjie Zhu ◽  
Jiajie Zhu ◽  
...  

Epigenomes ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 5 ◽  
Author(s):  
Ryohei Wada ◽  
Wataru Yoshida

N6-methyladenine modification (m6dA) has recently been identified in eukaryote genomic DNA. The methylation destabilizes the duplex structure when the adenine forms a Watson–Crick base pair, whereas the methylation on a terminal unpaired adenine stabilizes the duplex structure by increasing the stacking interaction. In this study, the effects of m6dA modification on the thermal stability of four distinct telomeric G-quadruplex (G4) structures were investigated. The m6dA-modified telomeric oligonucleotide d[AGGG(TTAGGG)3] that forms a basket-type G4 in Na+, d[(TTAGGG)4TT] that forms a hybrid-type G4 in K+ (Form-2), d[AAAGGG(TTAGGG)3AA] that forms a hybrid-type G4 in K+ (Form-1), and d[GGG(TTAGGG)3T] that forms a basket-type G4 with two G-tetrads in K+ (Form-3) were analyzed. Circular dichroism melting analysis demonstrated that (1) A7- and A19-methylation destabilized the basket-type G4 structure that formed in Na+, whereas A13-methylation stabilized the structure; (2) A15-methylation stabilized the Form-2 G4 structure; (3) A15- and A21-methylations stabilized the Form-1 G4 structure; and (4) A12-methylation stabilized the Form-3 G4 structure. These results suggest that m6dA modifications may affect the thermal stability of human telomeric G4 structures in regulating the biological functions.


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