Single molecule force spectroscopy in biology using the atomic force microscope

Abstract

The importance of forces in biology has been recognized for quite a while but only in the past decade have we acquired instrumentation and methodology to directly measure interactive forces at the level of single biological macromolecules and/or their complexes. This review focuses on force measurements performed with the atomic force microscope. A general introduction to the principle of action is followed by review of the types of interactions being studied, describing the main results and discussing the biological implications.

Direct AFM measurements of adhesion forces between calcium oxalate monohydrate and kidney epithelial cells in the presence of Ca2+ and Mg2+ ions

“…8 and Table 1 are standard deviations. Note that absolute values of the adhesion force obtained in the present paper (120-510 pN) agree well with the results 50-450 pN for the interaction forces between ligand and receptor pairs given by Zlatanova et al in the review paper [25]. Fig.…”

Assessing the Potential of Folded Globular Polyproteins As Hydrogel Building Blocks

“…A recent novel approach, that not only obviates these limitations but also harnesses their distinct functional properties, is to build hydrogels from tandem arrayed, folded globular proteins with known mechanical properties. 15,26,27 The mechanical properties of the native state of single, monodisperse proteins can be obtained by single molecule atomic force spectroscopy using the atomic force microscope (AFM) 28−31 or optical tweezers 32,33 as sensitive force transducers. In principle, information derived from single molecule force experiments allows for careful selection of a protein building block with the appropriate mechanical properties for the designed hydrogel.…”

Rapid Multitarget Immunomagnetic Separation through Programmable DNA Linker Displacement

“…Such behavior is not surprising, as DNA-DNA binding strength (20–50 pN for 10–30 base pairs) 15 is considerably lower than that of biotin-streptavidin bond (300 pN). 16 Poor bond stability can be partially addressed by using longer DNA probes, while maintaining binding specificity through careful sequence design. Furthermore, this effect may be negligible for separation of smaller analytes (proteins, bacteria), as shear forces decrease along with particle size.…”