Fragility of Bioprotectant Glass-Forming Systems in Extremophiles. (4th June 2009)

• Record Type: Journal Article
• Authors: Magazù, S.; Migliardo, F.
• Other Names: Crothers Derrick S. F. Academic Editor.
• Is Part Of: Journal of atomic, molecular, and optical physics. Volume 2009(2009)
• Publication Date: 2009-06-04
• Subjects: Nuclear physics -- Periodicals; Physical optics -- Periodicals; Molecules -- Periodicals; Atoms -- Periodicals; Atoms; Molecules; Nuclear physics; Physical optics; Periodicals; Electronic journals; 539.7
• DOI: 10.1155/2009/638063
• Languages: English
• ISSNs: 1687-9228

Abstract

Abstract : A central issue in the adaptation of proteins and enzymes to extreme conditions is the conservation of their functional state, which is characterized by a well-balanced compromise of stability and flexibility. In this review work an overview of elastic neutron scattering (ENS) findings on a class of bioprotectant glass-forming systems, such as trehalose and its homologous (maltose and sucrose) water mixtures, is presented as a function of temperature and concentration. ENS, in fact, allows to determine some remarkable quantities in order to characterize the correlation among dynamical properties, the flexibility and fragility of biomolecules. The experimental results have pointed out a dynamical transition, which shows a crossover in molecular fluctuations between harmonic and anharmonic dynamical regimes. The ENS findings allow to characterize both the trehalose rigidity and flexibility, which are strictly connected to its superior bioprotective effectiveness. In this frame the lowest flexibility and fragility character of trehalose/H 2 O mixture with respect to maltose and sucrose/H 2 O mixtures indicate a better attitude to encapsulate biostructures in more rigid and temperature insensitive structures in approaching the glass transition.