Direct Identification of Protein-Protein Interactions by Single-Molecule Force Spectroscopy

2016 ◽  
Vol 55 (45) ◽  
pp. 13970-13973 ◽  
Author(s):  
Andrés M. Vera ◽  
Mariano Carrión-Vázquez
Keyword(s):  
Single Molecule ◽  
Protein Interactions ◽  
Force Spectroscopy ◽  
Protein Protein Interactions ◽  
Direct Identification ◽  
Single Molecule Force Spectroscopy

scholarly journals Single molecule force spectroscopy studies of DNA denaturation by T4 gene 32 protein

2004 ◽  
Vol 18 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Mark C. Williams ◽  
Kiran Pant ◽  
Ioulia Rouzina ◽  
Richard L. Karpel
Keyword(s):  
Dna Binding ◽  
Optical Tweezers ◽  
Single Molecule ◽  
Protein Interactions ◽  
Force Spectroscopy ◽  
Melting Transition ◽  
Dna Molecules ◽  
Force Extension ◽  
Single Molecule Force Spectroscopy ◽  
Gene 32

Single molecule force spectroscopy is an emerging technique that can be used to measure the biophysical properties of single macromolecules such as nucleic acids and proteins. In particular, single DNA molecule stretching experiments are used to measure the elastic properties of these molecules and to induce structural transitions. We have demonstrated that double‒stranded DNA molecules undergo a force‒induced melting transition at high forces. Force–extension measurements of single DNA molecules using optical tweezers allow us to measure the stability of DNA under a variety of solution conditions and in the presence of DNA binding proteins. Here we review the evidence of DNA melting in these experiments and discuss the example of DNA force‒induced melting in the presence of the single‒stranded DNA binding protein T4 gene 32. We show that this force spectroscopy technique is a useful probe of DNA–protein interactions, which allows us to obtain binding rates and binding free energies for these interactions.

scholarly journals The effect of nanoscale surface curvature on the oligomerization of surface-bound proteins

2014 ◽  
Vol 11 (94) ◽  
pp. 20130818 ◽  
Author(s):  
M. Kurylowicz ◽  
H. Paulin ◽  
J. Mogyoros ◽  
M. Giuliani ◽  
J. R. Dutcher
Keyword(s):  
Single Molecule ◽  
Protein Interactions ◽  
Protein Function ◽  
Higher Order ◽  
Surface Curvature ◽  
Protein Protein Interactions ◽  
Single Molecule Force Spectroscopy ◽  
Adsorbed Proteins ◽  
Β Lactoglobulin

The influence of surface topography on protein conformation and association is used routinely in biological cells to orchestrate and coordinate biomolecular events. In the laboratory, controlling the surface curvature at the nanoscale offers new possibilities for manipulating protein–protein interactions and protein function at surfaces. We have studied the effect of surface curvature on the association of two proteins, α-lactalbumin (α-LA) and β-lactoglobulin (β-LG), which perform their function at the oil–water interface in milk emulsions. To control the surface curvature at the nanoscale, we have used a combination of polystyrene (PS) nanoparticles (NPs) and ultrathin PS films to fabricate chemically pure, hydrophobic surfaces that are highly curved and are stable in aqueous buffer. We have used single-molecule force spectroscopy to measure the contour lengths L c for α-LA and β-LG adsorbed on highly curved PS surfaces (NP diameters of 27 and 50 nm, capped with a 10 nm thick PS film), and we have compared these values in situ with those measured for the same proteins adsorbed onto flat PS surfaces in the same samples. The L c distributions for β-LG adsorbed onto a flat PS surface contain monomer and dimer peaks at 60 and 120 nm, respectively, while α-LA contains a large monomer peak near 50 nm and a dimer peak at 100 nm, with a tail extending out to 200 nm, corresponding to higher order oligomers, e.g. trimers and tetramers. When β-LG or α-LA is adsorbed onto the most highly curved surfaces, both monomer peaks are shifted to much smaller values of L c . Furthermore, for β-LG, the dimer peak is strongly suppressed on the highly curved surface, whereas for α-LA the trimer and tetramer tail is suppressed with no significant change in the dimer peak. For both proteins, the number of higher order oligomers is significantly reduced as the curvature of the underlying surface is increased. These results suggest that the surface curvature provides a new method of manipulating protein–protein interactions and controlling the association of adsorbed proteins, with applications to the development of novel biosensors.

scholarly journals Single Molecule Force Spectroscopy of Siloxanes

2021 ◽  
Vol 714 (3) ◽  
pp. 032023
Author(s):  
Ling Chen ◽  
Liya Yang ◽  
Chunxia Wang ◽  
Ting Zhu
Keyword(s):  
Single Molecule ◽  
Force Spectroscopy ◽  
Single Molecule Force Spectroscopy
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