Pressure is one of the fundamental parameters in thermodynamics, which can perturb physical properties of proteins as well as temperature. Here, I focused on molecular volume, partial molar volume, of proteins which depends on the hydration structure on the protein surface. Based on the thermodynamic relations, molecular volume can be estimated from the pressure, both of hydrostatic and osmotic pressure, dependence of equilibrium constants. In the protein folding of cytochrome c, the molecular volume change revealed that dehydration of hydrophobic heme group promotes the protein folding by increasing entropy. The dehydration of hydrophobic sites also facilitates the electron transfer from cytochrome c to cytochrome oxidase in the respiratory chain, which forms the “molecular breakwater” for the effective electron transfer pathway. By using pressure, we can get new insights into physical properties of proteins that can never be gained by other methodologies.

In this article, I introduce an analytical method named CS-PCA and its application for the destabilization mechanism of familial disease mutant of an amyloidogenic protein, β2-Microglobulin (β2m). Pressure concurrently induces several kinds of conformational changes of protein. We previously demonstrated that CS-PCA successfully decompose high-pressure NMR data, which contains mixed chemical shift data from these contributions, into individual contributions. Then, we applied this procedure in combination with MD simulation for the destabilization mechanism of the β2m mutant. Our approach revealed that the mutation induced the loosening of the inter-sheet packing and the network of correlated dynamics among some residues is relevant to the stability of inter-sheet packing.

There are various kinds of tissues in the body. Each tissue has different stiffness. Nowadays, it is shown that the importance of these stiffness not only homeostasis but differentiation from stem cells. These results made arising angle as the effect of pressure for the cell fate decisions and functions. In the ovary, we found that the importance of pressure to maintain the dormant state of primordial follicle.

Despite the fact that optimum environmental conditions are different with cell types, conventional cell preservation techniques are generally cryopreservation or hypothermic storage at atmospheric pressure. We have summarized the recent our study on the effect of temperature and pressure on the survival of adherent cells, aiming for short-term cell preservation and transportation in a closed system without frozen, medium change or CO₂ supply.

Decellularized tissue is promising as an ideal scaffold for tissue engineering. Decellularization techniques are classified by the chemicals used, such as acid or alkaline treatment, detergent treatment, or enzymatic digestion, and the physical methods used, such as snap freezing and mechanical agitation. As another candidate for a new decellularization treatment, we have developed the high-hydrostatic pressure (HHP) method. The unique characteristics of the HHP method are the destruction of cell membranes, uniform treatment, and short treatment time. Subsequent washing of the treated tissue can produce a decellularized tissue that does not adopt any chemical agents.