Exploring the structural properties and molecular mechanisms of cryoprotectants

Many organisms that live in extreme environments have developed mechanisms that protect them from environmental stresses. A common mechanism involves accumulation of sugars, known as protecting osmolytes, which allow organisms to survive sub-zero temperatures. This method is widely utilized in industry, medicine and nanotechnology to prolong the storage life of specific components. One such protecting osmolyte is glycerol, a sugar alcohol with three hydroxyl group, which is a rich and complex system for the study of hydrogen bonded fluids. While much work has been done to characterise glycerol’s dynamic properties a corresponding thorough examination of the structural properties of this molecule is lacking. In particular, little is known about the structural architecture of glycerol’s hydrogen network in aqueous solution. Furthermore, the molecular mechanism by which cryoprotectants like glycerol stabilise biological molecules is yet to be elucidated. We have completed a series of neutron diffraction experiments combined with computational modelling to reveal insight into the structural properties of this important system. We have completed a range of single molecule force spectroscopy experiments to probe the mechanical stability of proteins in cryoprotectant environments. By combining these two approaches we hope to shed light onto the molecular mechanisms of cryoprotection.