Mechanosensitive channels, inner membrane proteins of bacteria, open and close in response to mechanical stimuli such as changes in membrane tension during osmotic stress. In bacteria, these channels act as safety valves preventing cell lysis upon hypoosmotic cell swelling: the channels open under membrane tension to release osmolytes along with water. The mechanosensitive channel of small cond...

Cells of many organisms accumulate certain small organic molecules--called compatible and counteracting solutes, compensatory solutes, or chemical chaperones--in response to certain physical stresses. These solutes include certain carbohydrates, amino acids, methylamine and methylsulphonium zwitterions, and urea. In osmotic dehydrating stress, these solutes serve as cellular osmolytes. Unlike c...

An interesting observation, reported for transgenic plants that have been engineered to overproduce osmolytes, is that they often exhibit impaired growth in the absence of stress. As growth reduction and accumulation of osmolytes both typically result from adaptation, we hypothesized that growth reduction may actually result from osmolyte accumulation. To examine this possibility more closely, ...

Osmolytes are small organic compounds that affect protein stability and are ubiquitous in living systems. In the equilibrium protein folding reaction, unfolded (U) native (N), protecting osmolytes push the equilibrium toward N, whereas denaturing osmolytes push the equilibrium toward U. As yet, there is no universal molecular theory that can explain the mechanism by which osmolytes interact wit...

Bovine serum albumin (BSA) is an important transport protein of the blood and its aggregation/fibrillation would adversely affect its transport ability leading to metabolic disorder. Therefore, understanding the mechanism of fibrillation/aggregation of BSA and design of suitable inhibitor molecules for stabilizing its native conformation, are of utmost importance. The qualitative and quantitati...

BACKGROUND Hyperosmotic stress causes cell death through activation of apoptotic pathways if the protective osmolyte response is impaired. In this study we attempt to elucidate the molecular mechanisms of hypertonicity-induced apoptosis and the effect of major organic osmolytes upon those. METHODS Hypertonicity-induced changes in Bcl2-family protein abundance and the presence of cytochrome c ...

Single-molecule force spectroscopy has emerged as a powerful tool for studying the folding of biological macromolecules. Mechanical manipulation has revealed a wealth of mechanistic information on transient and intermediate states. To date, the majority of state assignment of intermediates has relied on empirical demarcation. However, performing such experiments in the presence of different osm...

Protective osmolytes are chemical compounds that shift the protein folding/unfolding equilibrium toward the folded state under osmotic stresses. The most widely considered protection mechanism assumes that osmolytes are depleted from the protein's first solvation shell, leading to entropic stabilization of the folded state. However, recent theoretical and experimental studies suggest that prote...