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Single-molecule atomic force microscopy on live cells compares aptamer and antibody rupture forces
Meghan B O'Donoghue1, Xiaoli Shi, Xiaohong Fang
1Department of Chemistry, Center for Research at the Bio/Nano Interface, UF Genetics Institute, University of Florida, Gainesville, FL 32611-7200, USA.
Analytical and Bioanalytical Chemistry
|January 27, 2012
Summary
Synthetic aptamers and natural antibodies exhibit comparable binding forces, with aptamer-protein binding at 46 pN and antibody-protein binding at 68 pN. This study resolves questions about aptamer binding robustness compared to antibodies.
Area of Science:
- Biochemistry
- Molecular Biology
- Biophysics
Background:
- Antibodies are natural proteins used for molecular recognition.
- Synthetic aptamers are emerging as alternatives to antibodies.
- Questions exist regarding the binding strength of aptamers versus antibodies.
Purpose of the Study:
- To quantitatively compare the binding forces of aptamers and antibodies to their target proteins.
- To address the debate on the binding robustness of synthetic aptamers.
Main Methods:
- Utilized single-molecule atomic force microscopy (AFM).
- Measured the rupture force between a target protein and its corresponding aptamer.
- Measured the rupture force between the same target protein and its corresponding antibody on live cell membranes.
Main Results:
- The rupture force between the aptamer and protein on live cell membranes was 46 ± 26 pN.
- The rupture force between the antibody and protein on live cell membranes was 68 ± 33 pN.
- The binding forces were found to be statistically comparable.
Conclusions:
- Synthetic aptamers demonstrate binding forces comparable to natural antibodies.
- The study provides empirical evidence supporting the use of aptamers as robust binding agents.
- AFM is a suitable technique for comparing molecular binding strengths.
