We determined the added enthalpic and entropic contributions of protective osmolytes to the folding of a model peptide into its native beta-hairpin state. In contrast to entropically driven steric "crowding", this study shows that sugars and polyols can act as protective osmolytes by primarily diminishing the unfavourable enthalpic contribution to folding.

Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is n...

In this brief review we discuss the evolution of recent thought regarding the role and mechanism of osmolytes with respect to protein stability. Osmolytes are naturally occurring intracellular compounds that change the protein folding landscape. Contributions from experiments are considered in the context of current theory and simulation results.

The key cytopathologies in the brains of Alzheimer's disease (AD) patients include mitochondrial dysfunction and energy hypometabolism, which are likely caused by the accumulation of toxic species of amyloid-beta (Abeta) peptides. This review discusses two potential approaches to delay the onset of AD. The first approach is use of diaminophenothiazines (e.g., methylene blue; MB) to prevent mito...

We present a study on the influence of the naturally occurring organic osmolytes tri-methylamine N-oxide (TMAO) and urea on the bulk structure of water using X-ray Raman scattering spectroscopy. Addition of TMAO is known to stabilize proteins in otherwise destabilizing aqueous urea solutions. The experimental X-ray Raman scattering spectra change systematically with increasing solute concentrat...

Protein solvation is the key determinant for isothermal, concentration-dependent effects on protein equilibria, such as folding. The required solvation information can be extracted from experimental thermodynamic data using Kirkwood-Buff theory. Here we derive and discuss general properties of proteins and osmolytes that are pertinent to their biochemical behavior. We find that hydration depend...

The cells in the renal medulla protect themselves from the extracellular hypertonicity in that region of the kidney by accumulating large amounts of sorbitol, inositol, glycerophosphorylcholine, and betaine. The system is uniquely active in this part of the body, but it represents a throwback to primitive mechanisms by which cells in virtually all organisms, including bacteria, yeasts, plants, ...

A liquid chromatography/mass spectrometry (LC/MS, electrospray ionisation) method has been developed for the quantification of nitrogenous osmolytes (N-osmolytes) in the particulate fraction of natural water samples. Full method validation demonstrates the validity of the method for measuring glycine betaine (GBT), choline and trimethylamine N-oxide (TMAO) in particulates from seawater. Limits ...

Cyanobacteria contribute significantly to the maintenance of flooded rice field fertility. In this investigation, the protective effect of osmolytes and antioxidative enzymes was studied on the paddy field cyanobacterial biofertilizer; Anabaena variabilis exposed to Malathion pesticide. With increasing concentration of malathion the test organism showed increased free radical mediated toxicity....