FRECHERO marisa Alejandra
congresos y reuniones científicas
Local structural indexes in water: A measure of relevance in hydration and biological water.
M.A. FRECHERO; L.M. ALARCÓN; E.P. SCHULZ; D. MALASPINA; G.A. APPIGNANESI
Congreso; IDMRCS-6th International Discussion Meeting on Relaxations in Complex Systems-; 2009
The fact that liquid water represents a mixture of two species (low density, structured molecules and high density unstructured ones, with the fraction of structured molecules increasing as temperature is decreased within the liquid and continuing in the supercooled regime) represents a notion with far-reaching consequences. A very interesting application of local structural indices can be performed for the study of water at interfaces and biological hydration water. Here we show that the first water layers (for example, water in contact with a graphite layer and the hydration shells of proteins) are more structured than subsequent layers and significantly more structured than the bulk (as determined by the distribution of the structural indices of the corresponding molecules). Also, these water molecules exhibit a dynamics that is considerably slower. This information could be of essence in biology, since it is expected that the structure and the dynamical behavior of the surface water layers around proteins also combined with the (de)-hydrating propensities of certain particular protein local structural motifs are related to aspects like protein binding and protein reactivity, and could help in areas like drug design.