title: Probing interactions between human lung adenocarcinoma A549 cell and its aptamers at single-molecule resolution.
abstract: Because cell-specific aptamers have high potential for biomedical applications, investigation of the interaction between cell and its aptamers may be of key importance for an improved understanding of biochemical processes. Herein, the interaction between human lung adenocarcinoma A549 cell and its four aptamers was explored using single-molecule force spectroscopy (SMFS). The values of the unbinding force varied from 117.1 to 171.0 pN at the loading rate of 1.8 × 10(5)  pN/s. Based on the dependence of singe molecule force on the atomic force microscopy loading rate, the corresponding kinetic parameters were obtained. The results revealed two activation barriers and two transient states in the unbinding process of aptamer/cell interaction. More importantly, the binding sites on A549 cells with its four aptamers were defined to be different using SMFS and flow cytometry. This work demonstrated that SMFS can be used as a powerful tool for exploring the aptamer/cell binding behavior at the single-molecule level, and may provide valuable information for the design and application of aptamer probes.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, College of Biology, Hunan University, Changsha, 410082, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Chenchen
authors.initials: C
authors.lastname: Zhou
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Yang
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000378:metabolism*; D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms / Q000737:chemistry / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D014407:Tumor Cells, Cultured
chemical_list: D052157:Aptamers, Nucleotide
keywords: A549 cell; aptamer; binding site; single-molecule force spectroscopy