Biophysical insights into the high pressure sensitivity of biomolecules

Abstract

Accurate folding and dynamics of biomolecules are substantially important for the functionality of living systems. As life can also be found in the realm of environmental extremes, biomolecules as well as their homo- and heterotypic interactions must withstand different environmental stresses including a wide range of temperature, pressure and salinity. For example, extreme conditions including high temperature, high hydrostatic pressure and high salinity can be found close to marine hydrothermal vents. Hence, adaptation strategies must exist to ensure life of extremophiles. Notably, globular proteins and double-stranded nucleic acids have been reported to be very pressure stable, whereas initial studies have shown that quaternary interactions of proteins and non-canonical structures of nucleic acids, being essential components of cellular entities, are rather pressure-sensitive. The present work shed light on the origin of the pressure sensitivity of the eukaryotic cytoskeleton by focusing on the components actin filaments and microtubules. More importantly, it addressed the issue of molecular strategies for pressure resistance. In particular, it focused on the role of accessory proteins of the cytoskeleton as well as the effects of macromolecular crowding and osmolytes, phenomena easily encountered inside cells. Further, the latter aspect was also investigated for a functional and temperature-sensitive ribonucleic acid hairpin known to regulate the gene expression in bacteria. To fundamentally understand the pressure effect on nucleic acids, the self-assembly reaction of guanosine-monophosphate as a single nucleotide was focus of the present work as well.