Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Mechanical Protein Functions

Mechanical Protein Functions

Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

SmartTrap: automated precision experiments with optical tweezers.

Nature methods·2026

Same author

From Quantum Mechanics to Coarse-Grained Models: Bridging the Gap toward Polymer Rational Design.

Journal of chemical theory and computation·2026

Same author

Determining the Effective DNA Charge Density from Nanopore Translocation Dynamics.

Nano letters·2026

Same author

Continuous-time random walk model for the diffusive motion of helicases.

QRB discovery·2025

Same author

Rational design of gold nanoparticles functionalized with aptamers for improved West Nile virus detection.

Nanoscale·2025

Same author

Temperature-dependent funnel-like DNA folding landscapes.

Nucleic acids research·2025

Search research articles

Related Experiment Video

Updated: Jun 22, 2026

Multiplexed Single-molecule Force Proteolysis Measurements Using Magnetic Tweezers

Multiplexed Single-molecule Force Proteolysis Measurements Using Magnetic Tweezers

Published on: July 25, 2012

Measurement of work in single-molecule pulling experiments.

Alessandro Mossa¹, Sara de Lorenzo, Josep Maria Huguet

¹Departament de Física Fonamental, Facultat de Física, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain. mossa@ub.edu

The Journal of Chemical Physics

|June 25, 2009

Summary

Researchers found that replacing total system work with subsystem work in free energy calculations can lead to up to 100% error. This highlights the importance of accurate work measurements in single-molecule experiments.

More Related Videos

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy

Published on: December 20, 2013

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements

Published on: May 12, 2023

Related Experiment Videos

Last Updated: Jun 22, 2026

Multiplexed Single-molecule Force Proteolysis Measurements Using Magnetic Tweezers

Multiplexed Single-molecule Force Proteolysis Measurements Using Magnetic Tweezers

Published on: July 25, 2012

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy

Published on: December 20, 2013

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements

Published on: May 12, 2023

Area of Science:

Thermodynamics
Single-molecule biophysics

Background:

Single-molecule experiments aim to determine free energy differences using fluctuation relations.
Work measurements along irreversible processes are crucial for these calculations.

Purpose of the Study:

To quantify the error in free energy estimates using the Jarzynski equality.
To investigate the impact of substituting total system work with subsystem work.

Main Methods:

Theoretical analysis of the Jarzynski equality.
Numerical simulations.
Experimental pulling experiments on DNA hairpins using optical tweezers.

Main Results:

Error in free energy estimates can reach 100% when only subsystem work is considered.
The magnitude of error depends on the number of experiments and data acquisition bandwidth.

Conclusions:

Accurate measurement of total system work is critical for reliable free energy calculations in single-molecule studies.
The findings emphasize the potential pitfalls in applying fluctuation relations when system boundaries are not properly accounted for.