Right- and left-handed helixes of poly[d(A-T)].poly[d(A-T)] investigated by infrared spectroscopy.

  title={Right- and left-handed helixes of poly[d(A-T)].poly[d(A-T)] investigated by infrared spectroscopy.},
  author={S. Adam and Jean Liquier and J. A. Taboury and E. Taillandier},
  volume={25 11},
The secondary structures of double-stranded poly[d(A-T)].poly[d(A-T)] in films have been studied by IR spectroscopy with three different counterions (Na+, Cs+, and Ni2+) and a wide variety of water content conditions (relative humidity between 100 and 47%). In addition to the A-, B-, C-, and D-form spectra, a new IR spectrum has been obtained in the presence of nickel ions. The IR spectra of Ni2+-poly[d(A-T)].poly[d(A-T)] films are analyzed by comparison with previously assigned IR spectra of… 

Raman spectroscopy of Z-form poly[d(A-T)].poly[d(A-T)].

Detailed spectroscopic data are presented reflecting the reorientation of the purine-deoxyribose entities (C2'-endo/anti----C3'-endo /syn), the modification of the phosphodiester chain, and the adenosine lines in the 1300-cm-1 region.

Z form of poly d(A-T).poly d(A-T) in solution studied by CD and UV spectroscopies.

The mechanism by which nickel ions induce the B----Z interconversion in the presence of high NaCl concentration is discussed and the new spectra are assigned to the Z conformation of poly d(A-T).

Infrared linear dichroism reveals that A-, B-, and C-DNAs in films have bases highly inclined from perpendicular to the helix axis.

It is demonstrated that the bases for DNA in films are highly inclined from perpendicular to the helix axis, even for B-DNA, which confirms earlier UV linear dichroism results for the orientation of the bases of DNA in solution.

The Z-conformation of poly(dA-dT).poly(dA-dT) in solution as studied by ultraviolet resonance Raman spectroscopy.

It is shown that RRS provides good marker bands for a left-handed helix and poly(dA-dT) can adopt a Z form in solution, which is observed in alternate purine-pyrimidine sequences does not require G-C base pairs.

Infrared and Raman studies show that poly(dA).poly(dT) and d(AAAAATTTTT)2 exhibit a heteronomous conformation in films at 75% relative humidity and a B-type conformation at high humidities and in solution.

It is concluded that both poly(dA).poly(dT) and d(AAAAATTTTT)2 adopt a fully heteronomous duplex geometry in cast films at low humidity.

B-X transition in synthetic and natural (dA-dT)n.(dA-dT)n sequences.

Circular dichroism and ultraviolet spectroscopy demonstrate that the X conformation is a double stranded form of poly(dA-dT) belonging presumably to the B family which, however has an altered base stacking.

Hydration effects of Ni(2+) binding to synthetic polynucleotides with regularly alternating purine-pyrimidine sequences.

  • B. Kankia
  • Biology, Chemistry
    Nucleic acids research
  • 2000
High precision ultrasonic and densimetric techniques have been used to study the interaction of Ni(2+)ions with right-handed poly[d(G-C] and poly[D(A-T]], revealing that Ni(1+)-EDTA complex formation can coordinate two atomic groups of poly [d( G-C)].

Reversal of the Z- to B-Conformation of Poly(dA-dT)•Poly(dA-dT) Induced by Netropsin and Distamycin A

The results suggest the preference of these AT-specific drugs for the B-form and the inability of Nt and Dst to form a stable complex with the Z-form of poly(dA-dT)•poly( dA- dT).

Circular dichroism of polynucleotides: Interactions of NiCl2 with poly(dA-dT).poly(dA-dT) and poly(dG-dC).poly(dG-dC) in a water-in-oil microemulsion.

The thermal behavior of the synthetic, high molecular weight, double stranded polynucleotides poly(dA-dT) andpoly(dG-dC) and polyGC, solubilized in the aqueous core of the quaternary water-in-oil cationic microemulsion CTAB, has been studied by means of circular dichroism and electronic absorption spectroscopies.

FT-IR spectroscopic study of the poly(amino2dA-dT) duplex in Mg(2+)-containing solution and in films.

It is shown that double helical poly(amino2dA-dT) goes into the same (or very closely related) conformation in dehydrated films as in solutions containing Mg2+.