Synopsis: Mechanical proteins

New techniques measure mechanical properties of proteins without damaging them.
Synopsis figure
Credit: Yong Wang

Nanorheology⎯the study of deformation of matter, particularly complex molecules, at the nanoscale⎯is beginning to give a clearer picture of the mechanics of biological macromolecules such as proteins and short DNA strands, both of which can act as molecular springs.

In their paper in Physical Review Letters, Yong Wang and Giovanni Zocchi at the University of California, Los Angeles, apply the techniques of rheology to the motion of charged gold nanoparticles tethered to a gold surface by globular proteins.

The particles are driven by an alternating current that produces deformations in the protein chain. With evanescent scattered light from a laser, the authors probe the frequency-controlled motion of the protein and determine its spring constant and friction coefficient. The deformations are small, leading to a strain of only around 1%, allowing the authors to measure mechanical properties of the protein without damaging it, an advantage over other common methods. – Sami Mitra


Features

More Features »

Announcements

More Announcements »

Subject Areas

Soft MatterBiological PhysicsInterdisciplinary Physics

Previous Synopsis

Soft Matter

Adapting to habitat

Read More »

Next Synopsis

Particles and Fields

A question of size

Read More »

Related Articles

Synopsis: Now You See Them, Now You Don’t
Soft Matter

Synopsis: Now You See Them, Now You Don’t

Whether topological defects form when a disk-shaped particle is placed in a liquid-crystal bath depends on the thickness of the particle. Read More »

Focus: Membrane Holes Can Shrink, Grow, or Stay Put
Soft Matter

Focus: Membrane Holes Can Shrink, Grow, or Stay Put

Pores in a polymer film do not change size over time if they have just the right diameter, according to experiments. Read More »

Focus: How Cells Remember Who They Are
Biological Physics

Focus: How Cells Remember Who They Are

A theoretical model of chromosome strands as polymers explains why chemical markers on genes can survive from one cell generation to the next. Read More »

More Articles