ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
CD spectra were obtained for eight synthetic double-stranded DNA polymers down to at least 175 nm in the vacuum uv. Three sets of sequence isomers were studied: (a) poly[d(A-C) · d(G-T)] and poly[d(A-G) · d(C-T)], (b) poly[d(A-C-C) · d(G-G-T)] and poly[d(A-C-G) · d(C-G-T)], and (c) poly[d(A) · d(T)], poly[d(A-T) · d(A-T)], poly[d(A-A-T) · d(A-T-T)], and poly[d(A-A-T-T) · d(A-A-T-T)]. There were significant differences in the CD spectra at short wavelengths among each set of sequence isomers. The (G · C)-containing sequences had the largest vacuum uv bands, which were positive and in the wavelength range of 180-191 nm. There were no large negative bands at longer wavelengths, consistent with the polymers all being in right-handed conformations. Among the set of sequences containing only A · T base pairs, poly[d(A) · d(T)] had the largest vacuum uv CD band, which was at 190 nm. This CD band was not present in the spectra of the other (A · T)-rich polymers and was absent from two first-neighbor estimations of the poly[d(A) · d(T)] spectrum obtained from the other three sequences. We concluded that the sequence dependence of the vacuum uv spectra of the (A · T)-rich polymers was due in part of the fact that poly[d(A) · d(T)] exists in a noncanonical B conformation.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360290204
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