Structure and Stability of a Dimeric G-Quadruplex Formed by Cyclic Oligonucleotides

We have studied the structure and stability of the cyclic dodecamer d<pGGGTTAGGGTTA>, containing two copies of the human telomeric repeat. In the presence of sodium, NMR data are consistent with a dimeric structure of the molecule in which two cycles self-associate forming a quadruplex with three guanine tetrads connected by edgewise loops. The two macrocycles are arranged in a parallel way, and the dimeric structure exhibits a high melting temperature. These results indicate that cyclization of the phosphodiester chain does not prevent quadruplex formation, although it affects the global topology of the quadruplex.

Download Full-text

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

Journal of Nucleic Acids ◽

10.4061/2011/857149 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 13

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.

Download Full-text

A Tem Study of Slip Systems in MoSi2/WSi2 Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089020 ◽

1991 ◽

Vol 49 ◽

pp. 942-943

Author(s):

Stuart A. Maloy

Keyword(s):

Solid Solution ◽

Solid Solution Hardening ◽

Slip Systems ◽

High Melting ◽

Group 14 ◽

Solution Hardening ◽

Brittle To Ductile Transition ◽

High Melting Temperature ◽

Tetragonal Unit Cell ◽

Structural Applications

MoSi2 has recently been investigated as a potential material for high temperature structural applications. It has excellent oxidation resistance up to 1700°C, a high melting temperature, 2030°C, and a brittle-to-ductile transition temperature at 900-1000°C. WSi2 is isomorphous with MoSi2 and has a body-centered tetragonal unit cell of the space group 14/mmm. The lattice parameters are a=3.20 Å and c=7.84 Å for MoSi2 and a=3.21 Å and c=7.88 Å for WSi2. Therefore, WSi2 was added to MoSi2 to improve its strength via solid solution hardening. The purpose of this study was to investigate the slip systems in polycrystalline MoSi2/WSi2 alloys.

Download Full-text

DNA polymerase δ stalls on telomeric lagging strand templates independently from G-quadruplex formation

Nucleic Acids Research ◽

10.1093/nar/gkt813 ◽

2013 ◽

Vol 41 (22) ◽

pp. 10323-10333 ◽

Cited By ~ 20

Author(s):

Justin D. Lormand ◽

Noah Buncher ◽

Connor T. Murphy ◽

Parminder Kaur ◽

Marietta Y. Lee ◽

...

Keyword(s):

Dna Polymerase ◽

Dna Polymerase Δ ◽

G Quadruplex ◽

Quadruplex Formation ◽

Lagging Strand

Download Full-text

TGF‐β‐induced fibrotic stress increases G‐quadruplex formation in human fibroblasts

FEBS Letters ◽

10.1002/1873-3468.13658 ◽

2019 ◽

Vol 593 (22) ◽

pp. 3149-3161 ◽

Cited By ~ 1

Author(s):

Priyanka Toshniwal ◽

Michelle Nguyen ◽

Aurore Guédin ◽

Helena Viola ◽

Diwei Ho ◽

...

Keyword(s):

Human Fibroblasts ◽

G Quadruplex ◽

Quadruplex Formation

Download Full-text

Sustainable Chiral Polyamides with High Melting Temperature via Enhanced Anionic Polymerization of a Menthone-Derived Lactam

Macromolecular Rapid Communications ◽

10.1002/marc.201600056 ◽

2016 ◽

Vol 37 (10) ◽

pp. 851-857 ◽

Cited By ~ 20

Author(s):

Malte Winnacker ◽

Michael Neumeier ◽

Xiaohan Zhang ◽

Christine M. Papadakis ◽

Bernhard Rieger

Keyword(s):

Melting Temperature ◽

Anionic Polymerization ◽

High Melting ◽

High Melting Temperature

Download Full-text

TT Dimerization and Its Effect on Human Telomere G-Quadruplex Formation

Bulletin of the Korean Chemical Society ◽

10.1002/bkcs.10316 ◽

2015 ◽

Vol 36 (6) ◽

pp. 1729-1732

Author(s):

In Sun Kim ◽

Young Jun Seo

Keyword(s):

G Quadruplex ◽

Quadruplex Formation ◽

Human Telomere

Download Full-text

Inhibition of Protein Synthesis Through RNA-Based Tandem G-Quadruplex Formation

Chemical Communications ◽

10.1039/d1cc02995a ◽

2021 ◽

Author(s):

Masaki Hagihara

Keyword(s):

Protein Synthesis ◽

Reverse Transcriptase ◽

Repeat Sequences ◽

Guanine Quadruplex ◽

G Quadruplex ◽

Inhibition Of Protein Synthesis ◽

Quadruplex Formation

Tandem guanine repeat sequences can adopt guanine quadruplex (G-quadruplex) structures and consecutive guanine repeat sequences can potentially afford multiple G-quadruplex structures. By using a reverse transcriptase stop assay and biophysical...

Download Full-text