Polarized electronic spectra of Z‐DNA single crystals
- 1 January 1990
- journal article
- research article
- Published by Wiley in Biopolymers
- Vol. 30 (1-2) , 151-163
- https://doi.org/10.1002/bip.360300115
Abstract
Polarized electronic absorption spectra of the (100) face of single crystals of the Z-form double helical duplex of d(m5CGUAm5CG) have been obtained from Kramers-Kronig analysis of reflection data. The c crystallographic axis is parallel to the helix axis and shows but weak absorption. The b axis is perpendicular to the helix axis and shows a structureless absorption band centered at 270 nm with an oscillator strength of 0.26. Calculations of the crystal spectra utilizing available transition moment data for the individual chromophores are carried through using the oriented gas model (no interbase interactions) and, again, employing all base-base interactions (point dipole) in the duplex. The calculated hypochromism of the 270 nm band is much less than the experimental value obtained from the crystal data. The crystal spectra appear to be representative of Z-form double helices of essentially infinite length and not of a collection of twelve base duplexes. No evidence for nπ* transitions polarized parallel to the helix axis is found.Keywords
This publication has 16 references indexed in Scilit:
- Electronic spectrum of the adenine chromophoreThe Journal of Physical Chemistry, 1990
- Polarization assignments in the 270-nm band of the adenine chromophoreThe Journal of Physical Chemistry, 1989
- Base tilt of B-form poly[d(G)]-poly[d(C)] and the B- and Z-conformations of poly[d(GC)]-poly[d(GC)] in solutionBiopolymers, 1986
- On the electronic spectrum of 1-methyluracilThe Journal of Physical Chemistry, 1986
- Transition-moment directions of protonated 1-methylcytosineJournal of the American Chemical Society, 1986
- The electronic spectrum of cytosineJournal of the American Chemical Society, 1985
- Electronic spectra of crystalline 9-ethylguanine and guanine hydrochlorideJournal of the American Chemical Society, 1977
- Additions and Corrections- Hypochromism in PolynucleotidesJournal of the American Chemical Society, 1961
- Hypochromism and Other Spectral Properties of Helical PolynucleotidesJournal of the American Chemical Society, 1961
- Hypochromism in Polynucleotides1Journal of the American Chemical Society, 1960