Z Helix-coil Transition of d(C-Br8G-C-G-C-Br8G) Studied by CD,1H-NMR and IR Spectroscopies

Taboury, Jean; Taillandier, E.; Lumbroso, Pascal; Neumann, Jean‐Michel; Tran-Dinh, S.; d’Estaintot, Béatrice Langlois; Huynh‐Dinh, Tam; Igolen, J.

doi:10.1080/07391102.1985.10507632

Cited by 18 publications

(7 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the temperature is raised, the conformation in this region of the molecule is altered to one in which such accessibility to exchange is diminished. This conformational change may be due to changes in the flexibility of the DNA backbone as the temperature is raised, as has been observed with other oligomers in the Z conformation (Hart-mann et al, 1983;Genest et al, 1987;Taboury et al, 1985). The changes with temperature observed in the 31P NMR spectra are consistent with this notion.…”

Section: Discussionsupporting

confidence: 80%

Temperature-dependent CD and NMR studies on a synthetic oligonucleotide containing a B-Z junction at high salt

Sheardy¹,

Winkle²

1989

Biochemistry

View full text Add to dashboard Cite

It is now accepted that two or more conformations may exist within the same DNA molecule, thereby generating conformational junctions. The presence of B-Z junctions between right- and left-handed DNA conformations has been detected in plasmids by a number of techniques. Preliminary characterization of the first example of a B-Z junction is a short DNA oligonucleotide has recently been reported [Sheardy, R. D. (1988) Nucleic Acids Res. 16, 1153-1167]. We report additional CD and NMR data that support the existence of the junction in this model oligomer. These studies indicate that only three base pairs are involved in the junction and only one of these is dramatically distorted. Furthermore, the NMR saturation-transfer experiments suggest the junction's internal motion is temperature dependent.

show abstract

Section: Discussionsupporting

confidence: 80%

Temperature-dependent CD and NMR studies on a synthetic oligonucleotide containing a B-Z junction at high salt

Sheardy¹,

Winkle²

1989

Biochemistry

View full text Add to dashboard Cite

show abstract

“…Past work with poly(dG-dC) (6,11,12) and analogs (13,14) has shown that infrared spectroscopy is a sensitive method for detecting the B and Z structures. The same structural forms have been shown to exist in hydrated films and in solutions (13).…”

Section: Introductionmentioning

confidence: 99%

Structural Forms and Transitions for the Complex of Mercury(II) with Poly(dG-dC)

Keller¹,

Hartman²

1987

Journal of Biomolecular Structure and Dynamics

View full text Add to dashboard Cite

Infrared spectroscopy was used to study hydrated double-helical poly(dG-dC) complexed with varying amounts of mercury(II). For one Hg(II) per ten nucleotide residues (r = 0.1), the B structure was stabilized and the B* structure was absent at high hydration. The Z structure did not form as hydration was reduced. For r = 0.2, the B and Z structures coexisted at high hydration and the transition to total Z structure was broad as hydration was reduced. Hg(II) was bound exclusively to the guanine residues probably at N3 or N7 for r less than or equal to 0.25. The cytosine residue did not protonate (at N3) as Hg(II) was bound to guanine. The addition of NaCl together with Hg(II) reduced the binding of Hg(II), stabilized the B structure at the highest hydration and caused a sharp transition between the B and Z structures as hydration was lowered. Hydration with D2O stabilized the Z structure for poly(dG-dC) complexed with HgCl2.

show abstract

“…Thermodynamic parameters were deter- [13]. Similarly to the 8-substituted purine oligoribonucleotides, the bulky 8-methyl groups force the oligonucleotide from the B-to the Z-DNA structure [5] [6]. This conformational change is neither observed in the case of the 7-substituted 7-deazaguanine oligonucleotides nor in the case of oligonucleotides containing 7-deazaguanine.…”

mentioning

confidence: 99%

“…In such a Z-DNA structure, the guanine residues adopt the syn/C(3')-endo conformation. The 8-substituents are located in the periphery of the left-handed helix and exposed to the solvent [5] [6].…”

mentioning

confidence: 99%

7‐Deazapurine Oligodeoxyribonucleotides: The effects of 7‐deaza‐8‐methylguanine on dna structure and stability

Seela

Chen

Mittelbach

1998

Helvetica Chimica Acta

View full text Add to dashboard Cite

Oligodeoxyribonucleotides containing 7-deaza-2'-deoxy-8-methylguanosine (mRc7G,; 2b) were prepared. For this purpose, the phosphonate 3a and the phosphoramidite 3b were synthesized and employed in solidphase oligodeoxyribonucleotide synthesis. The structures and the thermodynamic data of duplex formation of oligodeoxyribonucleotides containing 2b were investigated by temperature-dependent C D and UV spectra and compared with those containing 7-deaza-2'-deoxy-7-methylguanosine (m7c7G,) or 7-deaza-2'-deoxyguanosine (c,G,: 2a). In general. compound 2b reduces the duplex stability. In case of the sequence d(m8c7G-C), (IS), the B + Z transition was facilitated by the incorporation of 2b. Moreover, a single 7-deaza-8-methylguanine residue present in a n oiigodeoxyribonucleotide tract of guanine residues destabilizes the dG quadruplex significantly. This destabilization is more pronounced than in the case of 7-deazaguanine or 7-deaza-7-methylguanine.Introduction. -The purine residues bearing alkyl or halogen substituents at C(8) have a strong influence on the nucleoside conformation and ultimately on the structure of D N A [I-81. Single-crystal X-ray analysis has shown that the orientation around the N-glycosylic bond is often biased towards SJW in the case of 8-substituted guanine ribonucleosides [I -41. This is the result of steric repulsion between the 8-substituents and the sugar moiety. In the solid state, these nucleosides show a C(2')-endo pucker ('TJ and an intramolecular 0(5')-H. . N(3) H-bond [I -41. The 8-methylguanosine (la) and 2'-deoxy-8-methylguanosine (1 b) have been incorporated into oligonucleotides. These residues markedly stabilize the Z-conformation of the oligonucleotide duplex, even at low salt concentration [5-81. In such a Z-DNA structure, the guanine residues adopt the syn/C(3')-endo conformation. The 8-substituents are located in the periphery of the left-handed helix and exposed to the solvent [5] [6].Earlier, the role of 7-substituted 7-deazapurine nucleosides on the D N A structure and stability was studied [9-321. It was found that substituents at the 7-position have steric freedom within the major groove of B-DNA, thereby stabilizing the duplex. Now, the 8-substituted 7-deazapurine derivative, 7-deaza-2'-deoxy-8-methy1guanosine (m8c7G,; 2b), is incorporated [I 31 into oligonucleotides. For this molecule, a single-crystal X-ray structure has been reported which is the first solid-state structure of an 8-substituted purine 2'-deoxyribonucleoside related to 2'-deoxyguanosine. This structure shows a peculiarity. The glycosylic-bond orientation is anti and not syn as observed for 8-substituted guanine ribonucleosides [I 41. This manuscript reports on the structure and stability of oligonucleotides containing compound 2b within various sequence patterns which were obtained by solid-phase synthesis using phosphonate 3a or phosphoramidite 3b. The structural changes of single-stranded oligonucleotide chains, duplexes, and

show abstract

Z Helix-coil Transition of d(C-Br⁸G-C-G-C-Br⁸G) Studied by CD,¹H-NMR and IR Spectroscopies

Cited by 18 publications

References 35 publications

Temperature-dependent CD and NMR studies on a synthetic oligonucleotide containing a B-Z junction at high salt

Temperature-dependent CD and NMR studies on a synthetic oligonucleotide containing a B-Z junction at high salt

Structural Forms and Transitions for the Complex of Mercury(II) with Poly(dG-dC)

7‐Deazapurine Oligodeoxyribonucleotides: The effects of 7‐deaza‐8‐methylguanine on dna structure and stability

Contact Info

Product

Resources

About