ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Raman spectra of poly(rG), obtained from neutral aqueous solutions containing excess sodium counterions, are qualitatively different than spectra obtained from salt-free solutions. In the presence of a two-fold molar excess of Na+ (per phosphate group) the Raman spectrum of poly(iG) closely resembles that of the gel of Guo-5′-P and is characteristic of an ordered helical structure in which guanine residues are hydrogen bonded to one another. In the absence of added salt the spectrum of poly(rG) is characterized by unusual guanine ring frequencies which suggests a tautomeric or ionic modification of the ordinary (keto-amino) ring structure. Both the high-salt and no-salt forms of poly(rG) represent stable secondary structures as evidenced by the conformationally sensitive phosphodiester frequencies and by the absence of significant spectral changes on heating the solutions.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250010208
