Disaccharide effects on membranes and proteins in intact cells during drying

Anhydrobiotic organisms, organisms capable of surviving periods of extreme dehydration, are known to produce large amounts of non-reducing disaccharides with trehalose and sucrose being especially common. The ability of these organisms to survive desiccation shows a strong correlation with the presence and amount of sugar, resulting in the proposal that the disaccharides are responsible for the organisms' survival. Numerous studies have shown that disaccharides can protect liposomes, isolated biological membranes, and isolated proteins from damage during drying, but the sugars' capacity to function in a similar manner in intact cells has not been demonstrated directly. The purpose of the work presented here was to investigate the ability of trehalose and sucrose to stabilize both membranes and proteins in intact cells during drying. The yeast Saccharomyces cerevisiae and the bacteria Escherichia coli and Bacillus thuringiensis are used as model organisms. Fourier transform infrared spectroscopy was used to follow the asymmetric phosphate stretch in intact dry yeast, demonstrating that trehalose interacts with phospholipid molecules of the plasma membrane to lower the temperature of the phase transition in dry cells to a physiologically tolerable temperature. Changes in vibrational frequency of the CH...