Screening and Improvement of an Anti-VEGF DNA Aptamer

Molecules

Yoshihiko Nonaka¹  Koji Sode¹ 

[1] Department of Biotechnology & Life science, Tokyo University of Agriculture and Technology, 2-24-21 Naka Cho, Koganei, Tokyo, 1848588, Japan

关键词: aptamer;    cancer diagnosis;    sensor element;    VEGF₁₂₁;    VEGF₁₆₅;   

DOI  :  10.3390/molecules15010215

来源: mdpi

【 摘 要 】

To obtain an aptamer with a high affinity for vascular endothelial growth factor (VEGF), we focused on the receptor-binding domain (RBD) of VEGF as a target epitope. Three rounds of screening gave Vap7, which bound to the VEGF isoforms VEGF₁₂₁ and VEGF₁₆₅ with K_D values of 1.0 nM and 20 nM, respectively. Moreover, Vap7 showed specificity within the VEGF family. Secondary structure predictions and circular dicrhoism suggested that Vap7 folds into a G-quadruplex structure. We obtained a mutant aptamer that contains only this region of the aptamer sequence. This truncated mutant (V7t1) bound to both VEGF₁₂₁ and VEGF₁₆₅ with K_D values of 1.1 nM and 1.4 nM, respectively. Its sequence was 5'-TGTGGGGGTGGACGGGCCGGGTAGA-3', and it appeared to form a G-quadruplex structure. We also produced an aptamer heterodimer consisting of our previously derived aptamer (del5-1), which binds to the heparin-binding domain of VEGF, linked to V7t1. The resulting heterodimer bound strongly to VEGF₁₆₅ with a K_D value of 4.7 × 10² pM.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.