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Affiliation of Author(s):化学与生命科学学院

Teaching and Research Group:生物技术教研室

Journal:Biochemistry

Funded by:国家自然科学基金项目

Key Words:MEDIATED ELECTRON-TRANSFER; GOLD ELECTRODES; BASE-STACKING; B-FORM; ELECTROCHEMICAL REACTION; DISTANCE DEPENDENCE; HOPPING MECHANISM; ANTICANCER DRUG; HOLE TRANSPORT; GLASSY-CARBON

Abstract:Several factors can influence charge transport (CT)-mediated DNA, such as sequence, distance, base stacking, base pair mismatch, conformation, tether length, etc. However, the DNA context effect or how flanking sequences influence redox active drugs in the DNA CT reaction and later in DNA enzymatic repair and synthesis is still not well understood. The set of seven DNA molecules in this study have been characterized well for the study of flanking sequence effects. These DNA duplexes are formed from self-complementary strands and contain the common central four-base sequence 5'-A-G-C-T-3', flanked on both sides by either (AT)(n) or (AA)(n) (n = 2, 3, or 4) or AA(AT)(2). UV-vis, fluorescence, UV melting, circular dichroism, and cyclic voltammetry experiments were used to study the flanking sequence effect on CT-mediated DNA by using daunomycin or adriamycin cross-linked with these seven DNA molecules. Our results showed that charge transport was related to the flanking sequence, DNA melting free energy, and ionic strength. For (AA)(n) or (AT)(n) species of the same length, (AA)(n) series were more stable and more efficient CT was observed through the (AA)(n) series. The same trend was observed for (AA)(n) and (AT)(n) series at different ionic strengths, further supporting the idea that flanking sequence can result in different base stacking and modulate charge transport through these seven DNA molecules.

First Author:li xi

Indexed by:Journal paper

Volume:45

Issue:45

Page Number:1

Number of Words:1

ISSN No.:0006-2960

Translation or Not:no

Date of Publication:2006-09-04