ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Raman spectra have been recorded for poly(dG-dT) · poly(dA-dC) and poly(dA-dT) · poly(dA-dT) in low salt and at high concentrations of CsF. Poly(dG-dT) · poly(dA-dC) shows no change in the 682-cm-1 guanine mode, demonstrating the absence of the Z-structure at high salt. The 790-cm-1 phosphodiester symmetric stretch, however, shifts up 5 cm-1 in 4.3M CsF, suggesting a slight conformational change, associated with ion binding or hydration changes. Poly(dA-dT) · poly(dA-dT) shows an additional broad band at 816 cm-1, attributed to the phosphodiester modes associated with the C3′-endo deoxyribose units in the alternating B-structure. In this case, both the 841- and the 816-cm-1 asymmetric phosphodiester stretches, associated with the C2′- and C3′-endo units, shift down on addition of CsF in a sequential manner. Correlation of this sequence with that previously observed for the two 31P-nmr resonances, establishes that the phosphodiester stretching frequencies depend on the conformation of the 5′-sugar, and not on the 3′-sugar.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360240806
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