Force Spectroscopy with a Small Dithering of AFM Tip: A Method of Direct and Continuous Measurement of the Spring Constant of Single Molecules and Molecular Complexes

Chtcheglova, Lilia A.; Shubeita, George T.; Sekatskii, S. K.; Dietler, Giovanni

doi:10.1016/s0006-3495(04)74192-2

Cited by 65 publications

(49 citation statements)

References 60 publications

(63 reference statements)

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“…Of course, these two pairs of signals (viz. X,Y and amplitude and phase signals) are not independent but are related to each other according to the formulae (15)(16)(17)(18). A typical lock-in amplifier does not enable one to record both signal pairs simultaneously, but of course they can be restored (calculated) from each other, as illustrated in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…1, which in essence shows the original setup we used in a previous study to measure the spring constants of molecular complexes (16,17), slightly modified for the work presented here. In this study, we used a Nanoscope IV Picoforce AFM (Bruker, Billerica, MA).…”

Section: Materials and Materialsmentioning

confidence: 99%

“…Experimental data were retrieved, stored, and processed using in-house-written LabView (16,17) and Hooke (22) software.…”

Section: Materials and Materialsmentioning

confidence: 99%

See 2 more Smart Citations

Can Dissipative Properties of Single Molecules Be Extracted from a Force Spectroscopy Experiment?

Benedetti

Gazizova

Kulik

et al. 2016

Biophysical Journal

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We performed dynamic force spectroscopy of single dextran and titin I27 molecules using small-amplitude and low-frequency (40-240 Hz) dithering of an atomic force microscope tip excited by a sine wave voltage fed onto the tip-carrying piezo. We show that for such low-frequency dithering experiments, recorded phase information can be unambiguously interpreted within the framework of a transparent theoretical model that starts from a well-known partial differential equation to describe the dithering of an atomic force microscope cantilever and a single molecule attached to its end system, uses an appropriate set of initial and boundary conditions, and does not exploit any implicit suggestions. We conclude that the observed phase (dissipation) signal is due completely to the dissipation related to the dithering of the cantilever itself (i.e., to the change of boundary conditions in the course of stretching). For both cases, only the upper bound of the dissipation of a single molecule has been established as not exceeding 3,10 À7 kg=s. We compare our results with previously reported measurements of the viscoelastic properties of single molecules, and we emphasize that extreme caution must be taken in distinguishing between the dissipation related to the stretched molecule and the dissipation that originates from the viscous damping of the dithered cantilever. We also present the results of an amplitude channel data analysis, which reveal that the typical values of the spring constant of a I27 molecule at the moment of module unfolding are equal to 451:5 mN=m, and the typical values of the spring constant of dextran at the moment of chair-boat transition are equal to 30 À 50 mN=m.

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Section: Resultsmentioning

confidence: 99%

Section: Materials and Materialsmentioning

confidence: 99%

See 1 more Smart Citation

Can Dissipative Properties of Single Molecules Be Extracted from a Force Spectroscopy Experiment?

Benedetti

Gazizova

Kulik

et al. 2016

Biophysical Journal

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“…Thus we evaluate 80 pN as the nonspecific interaction level in our measurements at the 8×8 µm 2 scan range. Typical specific interaction between a single pair of antigen-antibody is 90 to 130 pN [20]. The non-specific interaction force as high as 80 pN may impede the acquisition of single-pair specific interactions.…”

Section: Affinity Mapping Against Tra-1-81antigen On Hes Cellsmentioning

confidence: 99%

Profiling TRA-1-81 antigen distribution on a human embryonic stem cell

Qiu

Xiang

et al. 2008

Biochemical and Biophysical Research Communications

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Human embryonic stem (hES) cells hold great promise in regenerative medicine. Although hES cells have unlimited self-renewal potential, they tend to differentiate spontaneously in culture. TRA-1-81 is a biomarker of undifferentiated hES cells. Quantitative characterization of TRA-1-81 expression level in a single cell helps capture the "turn-on" signal and understand the mechanism of early differentiation. Here we report on our examination of TRA-1-81 distribution and association on a hES cell membrane using an atomic force microscope (AFM). Our results suggest that aggregated distribution of TRA-1-81 antigen is characteristic for undifferentiated hES cells. We also evaluated the TRA-1-81 expression level at ~17800 epitopes and ~700 epitopes per cell on an undifferentiated cell and a spontaneously differentiated cell, respectively. The method in this study can be adapted in examining other surface proteins on various cell types, thus providing a general tool for investigating protein distribution and association at the single cell level.

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“…Further investigations are underway to obtain more detailed data to be fitted by using the wormlike chain model. 1,2 Our AFM technique provides a way to compare the protein adhesions with two different surfaces in a simple and direct way. The results have also demonstrated that by using our AFM technique we are able to investigate protein adhesion force measurements without damaging the natural elastic property of the molecules.…”

Section: Discussionmentioning

confidence: 99%

Atomic Force Microscopy Measurements of Bovine Serum Albumin Adhesion Forces on Surfaces

2008

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A novel, direct technique has been developed to measure the interactions of bovine serum albumin (BSA) on surfaces by using atomic force microscopy (AFM) in a liquid environment. We have been able to measure adhesion forces between proteins and substrate surfaces in phosphatebuffered saline (PBS) solution directly, without any modification to the substrate and the AFM tip. Two different surfaces have been used in the measurements: mica (hydrophilic surface) and polystyrene (hydrophobic surface). The results show that a polystyrene surface has larger adhesion forces to BSA than a mica surface. This is consistent with previous research, which demonstrated that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.

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Force Spectroscopy with a Small Dithering of AFM Tip: A Method of Direct and Continuous Measurement of the Spring Constant of Single Molecules and Molecular Complexes

Cited by 65 publications

References 60 publications

Can Dissipative Properties of Single Molecules Be Extracted from a Force Spectroscopy Experiment?

Can Dissipative Properties of Single Molecules Be Extracted from a Force Spectroscopy Experiment?

Profiling TRA-1-81 antigen distribution on a human embryonic stem cell

Atomic Force Microscopy Measurements of Bovine Serum Albumin Adhesion Forces on Surfaces

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