TY - JOUR

T1 - Luminescence excitation spectra reveal low-lying excited states in stacked adenine bases

AU - Kononov, A. I.

AU - Bukina, M. N.

N1 - Copyright: Copyright 2017 Elsevier B.V., All rights reserved.

PY - 2002/12

Y1 - 2002/12

N2 - Luminescence emission, polarization, and excitation spectra of polyadenylic acid (poly(A)) have been studied in room-temperature aqueous solution (pH 8). The temperature dependence of the luminescence of poly(A) at two different excitation wavelengths in the range 1070° C has also been studied and compared with that of adenosine 5′-monophosphate (AMP). It has been found that the luminescence excitation spectrum and the polarization curve of poly(A) solution reveal a low-intensity electronic transition at about 320 nm which is red- shifted by ∼0.9 eV from the maximum of the absorption spectrum at 260 nm. A model of two luminescent stacked forms is suggested. The difference in the ground state levels of these two stacked forms obtained from the temperature dependencies of the emissions is insignificant (∼1 kcal/mol). This means a lowering of the excited state of the stacked form with the 320 nm/420 nm absorption/emission bands by ∼0.9 eV as compared to the main form with the 260 nm/400 nm absorption/emission bands. The low-lying excited states suggest the stronger electronic coupling of the bases in a certain stacked form. It is proposed that such clusters of the stacked bases could provide the wire-like conductivity in the short segments of DNA.

AB - Luminescence emission, polarization, and excitation spectra of polyadenylic acid (poly(A)) have been studied in room-temperature aqueous solution (pH 8). The temperature dependence of the luminescence of poly(A) at two different excitation wavelengths in the range 1070° C has also been studied and compared with that of adenosine 5′-monophosphate (AMP). It has been found that the luminescence excitation spectrum and the polarization curve of poly(A) solution reveal a low-intensity electronic transition at about 320 nm which is red- shifted by ∼0.9 eV from the maximum of the absorption spectrum at 260 nm. A model of two luminescent stacked forms is suggested. The difference in the ground state levels of these two stacked forms obtained from the temperature dependencies of the emissions is insignificant (∼1 kcal/mol). This means a lowering of the excited state of the stacked form with the 320 nm/420 nm absorption/emission bands by ∼0.9 eV as compared to the main form with the 260 nm/400 nm absorption/emission bands. The low-lying excited states suggest the stronger electronic coupling of the bases in a certain stacked form. It is proposed that such clusters of the stacked bases could provide the wire-like conductivity in the short segments of DNA.

KW - Charge resonance

KW - Charge transfer

KW - DNA stacking

KW - Low-lying electronic states

KW - Luminescence excitation spectra

KW - Polyadenylic acid

UR - http://www.scopus.com/inward/record.url?scp=0036912797&partnerID=8YFLogxK

U2 - 10.1080/07391102.2002.10506865

DO - 10.1080/07391102.2002.10506865

M3 - Article

C2 - 12437385

AN - SCOPUS:0036912797

VL - 20

SP - 465

EP - 471

JO - Journal of Biomolecular Structure and Dynamics

JF - Journal of Biomolecular Structure and Dynamics

SN - 0739-1102

IS - 3

ER -