Experimental and computational studies of the effects of high hydrostatic pressure on biomolecular interactions.

Abstract

Understanding the thermodynamic mechanisms of adaptation of biomacromolecules to high hydrostatic pressure can help shed light on how piezophilic organisms can survive at pressures reaching over 1,000 atmospheres at the bottom of the oceans (Ando N, et al. Annu. Rev. Biophys. 2021:50:343). Here I will summarize our recent experimental and computational work on various aspects of the effects of high hydrostatic pressure on biomacromolecules. Particular emphasis will be made on the volume changes, ΔV, that accompany conformational transitions in biomacromolecules such as proteins, protein-ssDNA complexes, and dsDNA duplexes. The importance of ΔV comes from the fact that it defines the pressure dependence of stability ΔV = (dΔG/dP)T. Thus, the response of the system to changes in pressure is driven by Le Chatelier's principle: if volume changes upon unfolding are positive, increase in hydrostatic pressure will lead to an increase in stability, whereas if the changes are negative, the stability will decrease with the increase in hydrostatic pressure. The results will be discussed in terms of relative contributions of volumes changes associated with voids and hydration to the net volume changed that accompany conformational transitions in biomacromolecules.