Virtual Issue on Protein Crowding and Stability

Insights into the biochemical and biophysical mechanisms mediating the longevity of the transparent optics of the eye lens

“…At high protein concentrations, the SRO of the lens crystallin stabilized in a gel can decrease light scattering in comparison to that predicted for proteins acting as independent scatterers (5,7,69,75). Whilst close packing of lens cytoplasmic proteins can decrease light scattering, protein crowding is often associated with the formation of unstable oligomers, fibrils, aggregates, or gels (82)(83)(84)(85)(86). Lens fiber cells are exposed to a variety of stresses, including hypoxia, high ionic strength, changes in osmotic pressure, decreasing pH, and high protein concentration (87)(88)(89), as the HMW and WIF (Fig.…”

Influence of Nonspecific Interactions between Proteins and In Vivo Cytoplasmic Crowders in Facilitated Diffusion of Proteins: Theoretical Insights

“…, these macromolecules do not interact with the searching protein or the DNA in any manner, and their contribution to the search dynamics is entropically driven through excluded volume interactions. However, several pieces of evidence show that cellular crowding is not really “inert”, and these macromolecules may nonspecifically interact with the protein, affecting its native stability. ,− Senske et al have proposed a unified framework to describe the stabilizing effects of the macromolecular crowding on the proteins, which is enthalpy-driven rather than entropy-based volume exclusion effects alone . Their work strongly supports the existence of interactions between the protein and intracellular crowders.…”

“…Importantly, we again stress that supposedly “inert” macromolecular crowders such as PEG which are used in vitro tend to interact with the proteins. Several other studies are also focusing on the effect of macromolecular crowding on different biomolecules, their stability, and related biological and biochemical processes. ,, …”

“…Several other studies are also focusing on the effect of macromolecular crowding on different biomolecules, their stability, and related biological and biochemical processes. 52,54,55 Such protein−crowder interactions and their subsequent effect on the search dynamics can be observed commonly through in vivo studies. The facilitated diffusion of the lac repressor protein in the presence of the inducer molecules that act as bulk crowders within the medium of Escherichia coli bacteria was monitored using single-molecule techniques.…”