title: Modified capillary electrophoresis based measurement of the binding between DNA aptamers and an unknown concentration target.
abstract: The recognition of targets such as biomacromolecules, viruses and cells by their aptamers is crucial in aptamer-based biosensor platforms and research into protein function. However, it is difficult to evaluate the binding constant of aptamers and their targets that are hard to purify and quantify, especially when the targets are undefined. Therefore, we aimed to develop a modified capillary electrophoresis based method to determine the dissociation constant of aptamers whose targets are hard to quantify. A protein target, human thrombin, and one of its aptamers were used to validate our modified method. We demonstrated that the result calculated by our method, only depending on the aptamer's concentrations, was consistent with the classical method, which depended on the concentrations of both the aptamers and the targets. Furthermore, a series of DNA aptamers binding with avian influenza virus H9N2 were confirmed by a four-round selection of capillary electrophoresis-systematic evolution of ligands by exponential enrichment, and we identified the binding constant of these aptamers by directly using the whole virus as the target with the modified method. In conclusion, our modified method was validated to study the interaction between the aptamer and its target, and it may also advance the evaluation of other receptor-ligand interactions.
authors: Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China.
authors: Yue-Wei
authors: YW
authors: Zhang
authors: Hai-Yu
authors: HY
authors: Yan
authors: Ping
authors: P
authors: Fu
authors: Fei
authors: F
authors: Jiang
authors: Yao
authors: Y
authors: Zhang
authors: Wen-Xue
authors: WX
authors: Wu
authors: Jin-Xiang
authors: JX
authors: Li
mesh_terms: D052157:Aptamers, Nucleotide / Q000378:metabolism*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D053127:Influenza A Virus, H9N2 Subtype / Q000378:metabolism*; D008969:Molecular Sequence Data; D015203:Reproducibility of Results; D013917:Thrombin / Q000378:metabolism*
chemical_list: D052157:Aptamers, Nucleotide; D013917:Thrombin