新規フェロセン化ナフタレンジイミドを用いる均一溶液中でのシグナルオン型電気化学的DNase I検出

• Published in: Bunseki kagaku Vol. 68; no. 12; p. 953
• Main Authors: SATO, Shinobu, FUKUTAKI, Shuji, TAKENAKA, Shigeori
• Format: Journal Article
• Language: Japanese
• Published: Tokyo Japan Science and Technology Agency 05.12.2019
• Subjects: Absorption; Affinity; Alanine; Anions; Backbone; Binding; Cations; Deoxyribonucleic acid; Diffusion coefficient; Diimide; DNA; Electrochemical analysis; Ligands; Lysine; Mathematical analysis; Molecular weight; Synthesis
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.68.953

A simple DNase I detecting method was achieved under a homogenous medium containing DNA duplex and a newly synthesized ferrocenylnaphthalene diimide derivative (FND) carrying alanine (1) or alanine-lysine residue (2) as an electrochemical indicator. The binding affinity of 1 or 2 with double stranded DNA was 105 M−1 or 106 M−1 order, which was estimated from a Scatchard analysis calculated by its absorption change upon the addition of calf thymus DNA (CT-DNA). It was expected that 1 or 2 intercalated to double stranded DNA with a threading mode and electrostatic interaction of the linker ammonium cations of 1 or 2 with phosphate anions of the DNA duplex backbone. The largest current increase after a DNase I treatment was observed under the mixture in a ratio of [3]:[CT-DNA-bp] = 10 : 1 (bp: DNA concentration per base pair), where the distance between the bound ligands is expected to a 10 bp or 34 Å theoretically. When considering to be ca. 30 Å of DNase I size and decreasing of the current increase under an increased amount of 3, DNase I required over ten base pairs to access and digest with the DNA duplex. The current increase in the case of a mixture of 10 μM 1 or 2 and 100 μM CT-DNA was obtained 340 % or 640 %, respectively, after being treated with DNase I (final concentration: 2.0 × 10−3 U μL−1), which might be derived from an apperarent molecular weight or diffusion coefficient of the ligand bound DNA duplex and the detection limit of DNase I in the case of 1 or 2 was 2.0 × 10−5 or 2.0 × 10−9 U μL−1, respectively, where the detection limit for 2 was 104-times higher than that for 1.