Incorporation of O6-methylguanine restricts the conformational conversion of the human telomere G-quadruplex under molecular crowding conditions

2016 ◽  
Vol 52 (9) ◽  
pp. 1903-1906 ◽  
Author(s):  
Andong Zhao ◽  
Chuanqi Zhao ◽  
Hisae Tateishi-Karimata ◽  
Jinsong Ren ◽  
Naoki Sugimoto ◽  
...  
Keyword(s):  
Parallel Structure ◽  
Molecular Crowding ◽  
G Quadruplex ◽  
Human Telomere ◽  
Conformational Conversion

O6-methylguanine incorporation impeded the conformational conversion of G-quadruplex from a hybrid to a parallel structure under molecular crowding conditions.

scholarly journals Human telomere double G-quadruplex recognition by berberine-bisquinolinium imaging conjugates in vitro and in cells

2020 ◽  
Vol 158 ◽  
pp. 1299-1309
Author(s):  
Ting-Cong Liao ◽  
Tian-Zhu Ma ◽  
Suo-Bin Chen ◽  
Agostino Cilibrizzi ◽  
Meng-Jia Zhang ◽  
...  
Keyword(s):  
G Quadruplex ◽  
Human Telomere ◽  
In Cells

scholarly journals Characterization of a G-quadruplex from hepatitis B virus and its stabilization by binding TMPyP4, BRACO19 and PhenDC3

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Orsolya Réka Molnár ◽  
András Végh ◽  
Judit Somkuti ◽  
László Smeller
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Binding Constants ◽  
Temperature Stability ◽  
Cd Spectroscopy ◽  
Parallel Structure ◽  
Hybrid Form ◽  
B Virus ◽  
G Quadruplex

AbstractSpecific guanine rich nucleic acid sequences can form non-canonical structures, like the four stranded G-quadruplex (GQ). We studied the GQ-forming sequence (named HepB) found in the genome of the hepatitis B virus. Fluorescence-, infrared- and CD-spectroscopy were used. HepB shows a hybrid form in presence of K+, but Na+, Li+, and Rb+ induce parallel structure. Higher concentrations of metal ions increase the unfolding temperature, which was explained by a short thermodynamic calculation. Temperature stability of the GQ structure was determined for all these ions. Na+ has stronger stabilizing effect on HepB than K+, which is highly unusual. The transition temperatures were 56.6, 53.8, 58.5 and 54.4 °C for Na+, K+, Li+, and Rb+ respectively. Binding constants for Na+ and K+ were 10.2 mM and 7.1 mM respectively. Study of three ligands designed in cancer research for GQ targeting (TMPyP4, BRACO19 and PhenDC3) showed unequivocally their binding to HepB. Binding was proven by the increased stability of the bound form. The stabilization was higher than 20 °C for TMPyP4 and PhenDC3, while it was considerably lower for BRACO19. These results might have medical importance in the fight against the hepatitis B virus.

Molecular Crowding Regulates the Structural Switch of the DNA G-Quadruplex†

Biochemistry ◽  
2002 ◽  
Vol 41 (50) ◽  
pp. 15017-15024 ◽  
Author(s):  
Daisuke Miyoshi ◽  
Akihiro Nakao ◽  
Naoki Sugimoto
Keyword(s):  
Molecular Crowding ◽  
G Quadruplex

An intramolecular antiparallel G-quadruplex formed by human telomere RNA

2018 ◽  
Vol 54 (32) ◽  
pp. 3944-3946 ◽  
Author(s):  
Chao-Da Xiao ◽  
Tomokazu Shibata ◽  
Yasuhiko Yamamoto ◽  
Yan Xu
Keyword(s):  
Rna Sequence ◽  
First Report ◽  
G Quadruplex ◽  
Human Telomere

This is the first report of an antiparallel RNA G-quadruplex formed by a native RNA sequence.

scholarly journals The Effects of Molecular Crowding on the Structure and Stability of G-Quadruplexes with an Abasic Site

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Takeshi Fujimoto ◽  
Shu-ichi Nakano ◽  
Daisuke Miyoshi ◽  
Naoki Sugimoto
Keyword(s):  
Site Effects ◽  
Enthalpy Change ◽  
Molecular Crowding ◽  
Abasic Site ◽  
Structure And Stability ◽  
Quadruplex Structure ◽  
Abasic Sites ◽  
Crowding Effects ◽  
G Quadruplex ◽  
Quadruplex Formation

Both cellular environmental factors and chemical modifications critically affect the properties of nucleic acids. However, the structure and stability of DNA containing abasic sites under cell-mimicking molecular crowding conditions remain unclear. Here, we investigated the molecular crowding effects on the structure and stability of the G-quadruplexes including a single abasic site. Structural analysis by circular dichroism showed that molecular crowding by PEG200 did not affect the topology of the G-quadruplex structure with or without an abasic site. Thermodynamic analysis further demonstrated that the degree of stabilization of the G-quadruplex by molecular crowding decreased with substitution of an abasic site for a single guanine. Notably, we found that the molecular crowding effects on the enthalpy change for G-quadruplex formation had a linear relationship with the abasic site effects depending on its position. These results are useful for predicting the structure and stability of G-quadruplexes with abasic sites in the cell-mimicking conditions.

Sign in / Sign up

Export Citation Format

Share Document