Unravelling the Adaptation Mechanisms to High Pressure in Proteins

Abstract

Life is thought to have appeared in the depth of the sea under high hydrostatic pressure. Nowadays, it is known that the deep biosphere hosts a myriad of life forms thriving under high-pressure conditions. However, the evolutionary mechanisms leading to their adaptation are still not known. Here, we show the molecular bases of these mechanisms through a joint structural and dynamical study of two orthologous proteins. We observed that pressure adaptation involves the decoupling of protein–water dynamics and the elimination of cavities in the protein core. This is achieved by rearranging the charged residues on the protein surface and using bulkier hydrophobic residues in the core. These findings will be the starting point in the search for a complete genomic model explaining high-pressure adaptation.

Effects of Crowding and Cosolutes on Biomolecular Function at Extreme Environmental Conditions

“…Characteristic for all three is the high amount of intracellular crowding, which contributes to the stability of the cells. Extremophiles often, but not exclusively, belong to the domain of archaea, which have characteristic features permitting adaptation processes or structural and dynamical particularities allowing them to adopt to harsh external conditions . In the context of this review on crowding and its impact on biomolecular function, some of them will be discussed in more detail.…”

“…A similar trend is observed by the other relevant parameters obtained from the model, 146 such as the distance between potential wells, d (Figure 32A), which reports on the roughness of the protein's energy landscape, 207 the entropy difference ΔS (Figure 32B), which is connected to the hydration of the proteins, 138 and the free energy difference ΔG (Figure 32C) between the two states, calculated for T = 27 °C. In our previous study, 18 we showed that the decrease in d and the increase in ΔS for Tko PMI under high pressure corresponds to a general stiffening of the protein and to the loss of structural stability. This can also be observed in the current results for Tko PMI in the absence of TMAO.…”

“…Figure exhibits the total MSDs for all the samples. When TMAO is not present, the results are in line with preceding studies, Tba PMI being able to retain most of its dynamics under high-pressure conditions, while Tko PMI becomes significantly stiffer. Upon the addition of 1 M TMAO, the two proteins react in opposite ways.…”

“…The contrasting response of the two proteins to the addition of the osmolyte can be explained by the different amino-acidic compositions they present on their surfaces. We have shown that Tba PMI tends to avoid direct interactions with water by virtue of specific substitutions at the protein surface, which promote the formation of salt bridges and therefore decrease the availability of some residues to interact with water . This, in turn, decouples protein–water cooperative dynamics, which seems to be advantageous in the framework of pressure adaptation.…”

Extremophilic microbial metabolism and radioactive waste disposal

“…In response to pressure increases, microorganisms are also known to produce organic compounds known as piezolytes, that act to stabilise proteins under high hydrostatic pressure (Papini et al 2017 ). Another observed pressure adaptation includes the elimination of cavities in the protein core via decoupling of protein-water dynamics via rearranging protein surface charge residues to use bulkier hydrophobic residues in the core (Caliò et al 2022 ). It was previously believed that piezophiles only existed in pressurized environments, however, recent findings support a new hypothesis, that piezophiles have adopted a common adaptation strategy for dealing with multiple types of stressors (Wang et al 2021 ).…”