Exploring the structure and phase behavior of plasma membrane vesicles under extreme environmental conditions.

Not only drastic temperature- but also pressure-induced perturbations of membrane organization pose a serious challenge to the biological cell. Although high hydrostatic pressure significantly influences the structural properties and thus functional characteristics of cells, this has not prevented life from invading the high pressure habitats of marine depths where pressures up to the 100 MPa level are encountered. Here, the temperature- and pressure-dependent structure and phase behavior of giant plasma membrane vesicles have been explored in the absence and presence of membrane proteins using a combined spectroscopic and microscopic approach.

Probing volumetric properties of biomolecular systems by pressure perturbation calorimetry (PPC)--the effects of hydration, cosolvents and crowding.

Pressure perturbation calorimetry (PPC) is an efficient technique to study the volumetric properties of biomolecules in solution. In PPC, the coefficient of thermal expansion of the partial volume of the biomolecule is deduced from the heat consumed or produced after small isothermal pressure-jumps. The expansion coefficient strongly depends on the interaction of the biomolecule with the solvent or cosolvent as well as on its packing and internal dynamic properties.