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Effects of Multiple-Bond Ruptures on Kinetic Parameters Extracted from Force Spectroscopy Measurements: Revisiting Biotin-Streptavidin Interactions
- Source :
- Biophysical Journal. 95(8):3964-3976
- Publication Year :
- 2008
- Publisher :
- Elsevier BV, 2008.
-
Abstract
- Force spectroscopy measurements of the rupture of the molecular bond between biotin and streptavidin often results in a wide distribution of rupture forces. We attribute the long tail of high rupture forces to the nearly simultaneous rupture of more than one molecular bond. To decrease the number of possible bonds, we employed hydrophilic polymeric tethers to attach biotin molecules to the atomic force microscope probe. It is shown that the measured distributions of rupture forces still contain high forces that cannot be described by the forced dissociation from a deep potential well. We employed a recently developed analytical model of simultaneous rupture of two bonds connected by polymer tethers with uneven length to fit the measured distributions. The resulting kinetic parameters agree with the energy landscape predicted by molecular dynamics simulations. It is demonstrated that when more than one molecular bond might rupture during the pulling measurements there is a noise-limited range of probe velocities where the kinetic parameters measured by force spectroscopy correspond to the true energy landscape. Outside this range of velocities, the kinetic parameters extracted by using the standard most probable force approach might be interpreted as artificial energy barriers that are not present in the actual energy landscape. Factors that affect the range of useful velocities are discussed.
- Subjects :
- Streptavidin
Models, Molecular
Analytical chemistry
Biophysics
Biotin
02 engineering and technology
010402 general chemistry
Kinetic energy
01 natural sciences
Molecular physics
Dissociation (chemistry)
chemistry.chemical_compound
Molecular dynamics
Spectroscopy, Imaging, Other Techniques
Molecule
Computer Simulation
Quantitative Biology::Biomolecules
Spectrum Analysis
Force spectroscopy
Energy landscape
021001 nanoscience & nanotechnology
0104 chemical sciences
Biomechanical Phenomena
Kinetics
chemistry
Covalent bond
0210 nano-technology
Caltech Library Services
Subjects
Details
- ISSN :
- 00063495
- Volume :
- 95
- Issue :
- 8
- Database :
- OpenAIRE
- Journal :
- Biophysical Journal
- Accession number :
- edsair.doi.dedup.....9a6dbc3f744e57934ef9567964f357d5
- Full Text :
- https://doi.org/10.1529/biophysj.108.133900