PulseExploreJournal ClubDebatesTrendingResearchersJournals
Instagram
HomeExploreJournal ClubTrending
Synapse
⌘+K
Synapse
January 1, 1981Nucleic Acids Research287 citationsOpen Access

The high salt form of poly(dG-dC)·poly(dG-dC) is left-handed Z-DNA: Raman spectra of crystals and solutions

View Full Paper
TTThomas J. ThamannRLR. C. LordAWAndrew H.‐J. Wang

Key Points

  • Determine the structural conformation of aqueous poly(dG-dC)·poly(dG-dC) under high-salt conditions by comparing its Raman spectrum to crystalline d(CpGpCpGpCpG).
  • Measured laser-Raman spectra of crystalline d(CpGpCpGpCpG) alongside aqueous poly(dG-dC)·poly(dG-dC) in 4M NaCl (high salt) and 0.1M NaCl (low salt) solutions.
  • Compared spectral vibrational bands across crystal and solution states to identify salt-induced conformational transitions.
  • The Raman spectrum of high-salt (4M NaCl) poly(dG-dC) matches crystalline d(CpGpCpGpCpG), confirming the aqueous polymer adopts the left-handed Z-DNA conformation.
  • The low-salt (0.1M NaCl) spectrum differed substantially from the high-salt form, maintaining classic right-handed B-DNA characteristics.
  • A unique guanine Raman band emerged at 625 cm⁻¹ in the high-salt form, providing a specific marker for qualitative and quantitative detection of Z-DNA.

Abstract

The laser-Raman spectra of crystalline d(CpGpCpGpCpG) and of aqueous poly(dG-dC).poly(dG-dC) in high salt (4M NaCl) and low salt (0.1M NaCl) solutions have been measured and compared. The spectra of the crystal and the high-salt solution show a striking congruence, which indicates clearly that the high-salt form of the aqueous polymer has the left-handed Z-DNA structure of the crystalline oligomer. These two spectra differ substantially from that of the low-salt form of the polymer, which has been found previously to have spectral characteristics of the B-form of DNA. The high salt spectrum shows a unique line due to guanine residues at 625 cm-1 which should be useful for qualitative and possibly quantitative assessment of the amount of Z-structure present in a sample of DNA.

Ask AI
Helpful
Bookmark
Share
View Full Paper

Cite This Study

Thamann et al. (1981) studied this question.

synapsesocial.com/papers/69d9603500ab073a2783640dhttps://doi.org/10.1093/nar/9.20.5443
Ask AI
Helpful
Bookmark
Share
View Full Paper

Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

  1. 1The tetramer d(CpGpCpG) crystallizes as a left-handed double helix.1980 · 180 citations
  2. 2Conformation change of Poly(dG-dC)center dot Poly(dG-dC) in cationic polyamine liposome complexes: Effect of charge density and flexibility of amine chains in headgroups2000
  3. 3Formation of left-handed helices by C2′-fluorinated nucleic acids under physiological salt conditions2024 · 3 citations
  4. 4The Raman spectra of left-handed DNA oligomers incorporating adenine-thymine base pairs1984 · 77 citations
  5. 5Cation- and sequence length-dependent kinetics for B-/Z-DNA transition2026