Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Previous Article in Special Issue
Pharmaceuticals 2013, 6(9), 1082-1093; doi:10.3390/ph6091082
Article

Structural and Affinity Analyses of G-Quadruplex DNA Aptamers for Camptothecin Derivatives

1, 1, 1, 1, 1,2, 1,2,*  and 3,4
Received: 1 July 2013; in revised form: 11 August 2013 / Accepted: 26 August 2013 / Published: 29 August 2013
(This article belongs to the Special Issue Aptamer-Based Therapeutics)
View Full-Text   |   Download PDF [783 KB, updated 30 August 2013; original version uploaded 29 August 2013]
Abstract: We recently selected DNA aptamers that bind to camptothecin (CPT) and CPT derivatives from a 70-mer oligodeoxyribonucleotide (ODN) library using the Systematic Evolution of Ligands by EXponential enrichment (SELEX) method. The target-binding activity of the obtained 70-mer CPT-binding DNA aptamer, termed CA-70, which contains a 16-mer guanine (G)-core motif (G3TG3TG3T2G3) that forms a three-tiered G-quadruplex, was determined using fluorescence titration. In this study, truncated fragments of CA-70 that all have the G-core motif, CA-40, -20, -19, -18A, -18B, -17, and -16, were carefully analyzed. We found that CA-40 retained the target-binding activity, whereas CA-20, -19, and -18B exhibited little or no binding activities. Further, not only CA-18A but also the shorter length fragments CA-17 and -16 clearly retained the binding activity, indicating that tail strands of the G-quadruplex structure can significantly affect the target binding of G-quadruplex DNA aptamers. Further analyses using circular dichroism (CD) spectroscopy and fluorescence polarization (FP) assay were conducted to investigate the structure and affinity of G-quadruplex DNA aptamers.
Keywords: DNA aptamer; G-quadruplex; camptothecin (CPT); circular dichroism (CD) spectroscopy; fluorescence titration; fluorescence polarization (FP) assay DNA aptamer; G-quadruplex; camptothecin (CPT); circular dichroism (CD) spectroscopy; fluorescence titration; fluorescence polarization (FP) assay
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Fujita, H.; Imaizumi, Y.; Kasahara, Y.; Kitadume, S.; Ozaki, H.; Kuwahara, M.; Sugimoto, N. Structural and Affinity Analyses of G-Quadruplex DNA Aptamers for Camptothecin Derivatives. Pharmaceuticals 2013, 6, 1082-1093.

AMA Style

Fujita H, Imaizumi Y, Kasahara Y, Kitadume S, Ozaki H, Kuwahara M, Sugimoto N. Structural and Affinity Analyses of G-Quadruplex DNA Aptamers for Camptothecin Derivatives. Pharmaceuticals. 2013; 6(9):1082-1093.

Chicago/Turabian Style

Fujita, Hiroto; Imaizumi, Yuri; Kasahara, Yuuya; Kitadume, Shunsuke; Ozaki, Hiroaki; Kuwahara, Masayasu; Sugimoto, Naoki. 2013. "Structural and Affinity Analyses of G-Quadruplex DNA Aptamers for Camptothecin Derivatives." Pharmaceuticals 6, no. 9: 1082-1093.


Pharmaceuticals EISSN 1424-8247 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert