Tetrakis-acridinyl peptide: distance dependence of photoinduced electron transfer in deoxyribonucleic acid assemblies

Keiji Mizuki; Takahiko Nojima; Bernard Juskowiak; Shigeori Takenaka

doi:10.1016/j.aca.2006.05.045

Tetrakis-acridinyl peptide: distance dependence of photoinduced electron transfer in deoxyribonucleic acid assemblies

Anal Chim Acta. 2006 Sep 18;578(1):88-92. doi: 10.1016/j.aca.2006.05.045. Epub 2006 May 22.

Authors

Keiji Mizuki¹, Takahiko Nojima, Bernard Juskowiak, Shigeori Takenaka

Affiliation

¹ Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 812-8581, Japan.

PMID: 17723698
DOI: 10.1016/j.aca.2006.05.045

Abstract

The distance dependence of photoinduced electron transfer in deoxyribonucleic acid (DNA) duplex was investigated using the "TAP cassette" systems of the general formula (AT)6A(n)XA(9-n) (X denote guanine (G) or cytosine (C)). The tetrakis-9-acridinyl peptide (TAP) binds tightly with (AT)6 duplex region showing strong fluorescence that was not quenched by the A(n)XA(9-n) single-stranded region. Quenching was observed after duplex formation with the complementary T(9-n)XT(n) strand (G-C pairing), showing clear dependence on the distance between the TAP and a guanine. An extremely low beta value of 0.22 was obtained in our electron transfer (ET) system that suggests exceptional good mediation of ET process. Experiments with G-mismatches showed negligible quenching for systems with guanine separated by more than one AT base pair that indicated rather inefficient ET process for duplexes containing disrupted pi-electronic system.