Collective THz dynamics in living Escherichia coli cells

Water Collective Dynamics in Whole Photosynthetic Green Algae as Affected by Protein Single Mutation

“…42 It was supposed that the protein surface strongly affects the damping because the structure of the hydration water around the biomolecules comes to be more disordered with respect to the bulk water and therefore the excitation modes are sustained in a different way. 37,32 In all cases, the damping values are always higher than in bulk water, confirming that protein molecules are a perturbing agent of the aqueous solvent, capable of introducing novelties in the normally well-defined and ordered structure of water molecules and their hydrogen bond network. With this picture in mind, we establish that single-point mutation reveals somehow that collective density fluctuations, through the water network, might provide important insight on the transmission of information possibly correlated to biological functionality.…”

“…Here we find the same power law exponents, α = 2.1 and 1.9 for the wild-type Chlamydomonas and theI163N mutant cells, respectively, but larger C factors: 40 and 30 for the wild-type Chlamydomonas and the I163N mutant cells, respectively. Taking into account previous published results, , it is possible to speculate that high damping implies a denser and/or stiffer local environment. The higher the damping, the faster the propagating waves die.…”

“…To shed light on the impact of structural fluctuations (effects) due to single point mutation on larger scale properties, we investigated intracellular water collective dynamics in whole photosynthetic algae cells. It is a reasonable assumption to imagine that, since these collective excitations exist − and propagate with thermal energies, they will have an effect on the overall dynamics of the hydrated macromolecule and its biological activity.…”

“…The presence in the water dynamics of collective modes belonging to the protein was demonstrated by a MD simulation study investigating the longitudinal and transverse modes propagating in the system . It was supposed that the protein surface strongly affects the damping because the structure of the hydration water around the biomolecules comes to be more disordered with respect to the bulk water and therefore the excitation modes are sustained in a different way. , …”

Hydration state inside HeLa cell monolayer investigated with terahertz spectroscopy

“…Spectroscopic methods, such as NMR, 6 quasi-elastic neutron scattering (QENS), 7,8 and incoherent neutron scattering (INS) [9][10][11] have been used in the last decade to quantitatively determine the hydration state of monocellular organisms (i.e., Escherichia coli and Haloarcula marismortui) and human red blood cells. These studies show that 85%-90% of intracellular water behaves in a bulk-like fashion, while the remaining water molecules (classified as hydration water) exhibit more retarded reorientation and translation dynamics than that of bulk water.…”