Related Experiment Video
Updated: May 16, 2026

Study of Protein Dynamics via Neutron Spin Echo Spectroscopy
Published on: April 13, 2022
Slow dynamics and structure in jammed milk protein suspensions
Peggy Thomar1, Dominique Durand, Lazhar Benyahia
1LUNAM Université du Maine, IMMM UMR-CNRS, 72085 le Mans Cedex 9, France.
Abstract:
The dynamic mechanical properties and the structure of dense suspensions of sodium caseinate were investigated using oscillatory shear theology and confocal laser scanning microscopy, respectively. Caseins are the most abundant milk proteins and form in the absence of calcium phosphate small star-like particles with radii of about 10 nm. The viscosity increases strongly with increasing protein concentration above -80 g L(-1) due to jamming of the particles. The viscosity increase is stronger at lower temperatures, caused by a strong decrease in the terminal relaxation time with increasing temperature. Addition of calcium ions introduces an attractive interaction that induces phase separation above a critical calcium concentration. Increasing the CaCl2 concentration leads to an increase in the terminal relaxation time, but to a decrease in the high frequency elastic modulus. The effect of adding CaCl2 is stronger at higher temperatures.
Related Concept Videos
Colloids and Suspensions
Colloids
Protein Dynamics in Living Cells
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
The Colloidal State
Colloidal precipitates
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...

