Molecular Mechanisms of Survival Strategies in Extreme Conditions

Abstract

Today, one of the major challenges in biophysics is to disclose the molecular mechanisms underlying biological processes. In such a frame, the understanding of the survival strategies in extreme conditions received a lot of attention both from the scientific and applicative points of view. Since nature provides precious suggestions to be applied for improving the quality of life, extremophiles are considered as useful model-systems. The main goal of this review is to present an overview of some systems, with a particular emphasis on trehalose playing a key role in several extremophile organisms. The attention is focused on the relation among the structural and dynamic properties of biomolecules and bioprotective mechanisms, as investigated by complementary spectroscopic techniques at low- and high-temperature values.

Self-Assembly Processes in Hydrated Montmorillonite by FTIR Investigations

“…As far as the hydrated samples are concerned, in the present work we address the attention to the OH stretching band, which interests the frequency range of 2700-3900 cm −1 . In particular, the FTIR spectra are observed as a function of time ( Figure 5), and then deconvoluted into Gaussian components; finally, their time dependence is discussed [49][50][51][52][53][54][55][56][57]. For a comparison, the spectral profiles were normalized.…”

Phenolics and antioxidant activity of freeze-dried sour cherry puree with addition of disaccharides

“…In the presence of trehalose water molecules are arranged in a particular configuration, which avoids ice formation, so preserving biomolecules from damage due to freezing and cooling. Addition of trehalose, in respect to maltose and especially sucrose, completely destroys the tetrahedral intermolecular network of water, which by lowering the temperature would give rise to ice (Wang & Haymet, 1998;Magazù et al, 2005;Magazù et al, 2008;Cesaro et al, 2004;Magazù et al, 2007;Uchida et al, 2007;Magazù et al, 2012). Also, the study of the dynamical properties of trehalose water mixtures has shown that the diffusion of water is strongly affected by trehalose and that trehalose and water form a unique entity, creating a rigid environment where biomolecules can be protected and which have superior structural resistance to thermal stress (Magazù et al, 2012).…”

“…Addition of trehalose, in respect to maltose and especially sucrose, completely destroys the tetrahedral intermolecular network of water, which by lowering the temperature would give rise to ice (Wang & Haymet, 1998;Magazù et al, 2005;Magazù et al, 2008;Cesaro et al, 2004;Magazù et al, 2007;Uchida et al, 2007;Magazù et al, 2012). Also, the study of the dynamical properties of trehalose water mixtures has shown that the diffusion of water is strongly affected by trehalose and that trehalose and water form a unique entity, creating a rigid environment where biomolecules can be protected and which have superior structural resistance to thermal stress (Magazù et al, 2012). Investigating disaccharide (trehalose, sucrose and maltose) water systems confirmed that trehalose molecules have a greater inhibitory effect than sucrose on the growth of ice crystals (Uchida et al, 2007) and that aqueous trehalose has a larger amount of unfrozen water content in comparison with the other disaccharide systems (Furuki, 2002).…”

“…Maltose and trehalose are less sweet than the sucrose and previous studies have shown a positive effect of these sugars on the preservation of compounds such as polyphenols. In addition, it has been proven that sugars are behaving differently at low temperature and that behavior is related to the structure of the disaccharides (Wang & Haymet, 1998;Magazù, Migliardo, & RamirezCuesta, 2005;Magazù, Migliardo, & Telling, 2008;Cesaro, Magazù, Migliardo, Sussich, & Vadal a, 2004;Magazù, Migliardo, & RamirezCuesta, 2007;Uchida, Nagayama, Shibayama, & Gohara, 2007;Magazù, Migliardo, Gonzalez, Mondelli, Parker, & Vertessy 2012). Chosen disaccharides are isomers and were used for preparation of the freeze-dried sour cherry puree to investigate their influence on phenolic compounds and antioxidant potential.…”

Plant Desiccation Tolerance and its Regulation in the Foliage of Resurrection “Flowering-Plant” Species

“…Sugar accumulation has been observed during drought stress in transgenic tobacco expressing the E. coli TPS gene [128] providing indirect evidence of the potential involvement of the trehalose biosynthesis pathway in some aspects of vitrification observed in desiccation tolerance. Trehalose has a high glass transition temperature, and forms strong hydrogen bonds with water [129]. Furthermore trehalose is thought to provide stabilisation to proteins, and prevents membrane fusion [130].…”