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SANTIAGO DEL ESTERO ARGENTINA 2016. AQUAOMICS AND WATERONS: WATER INFORMATIONAL UNITS AT THE MEMBRANE INTERPHASE. E. Anibal Disalvo. Laboratory of Biointerphases and Biomimetic Systems CIBAAL FAyA- FCEyT UNSE-CONICET Santiago del Estero Argentina. disalvoanibal@yahoo.com.ar. CELLS.
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SANTIAGO DEL ESTERO ARGENTINA 2016
AQUAOMICS AND WATERONS: WATER INFORMATIONAL UNITS AT THE MEMBRANE INTERPHASE E. Anibal Disalvo Laboratory of Biointerphases and Biomimetic Systems CIBAAL FAyA- FCEyT UNSE-CONICET Santiago del Estero Argentina disalvoanibal@yahoo.com.ar
WHAT TYPE OF WATER IS RELEVANT FOR CELL PERFORMANCE WITH SUCH PROPERTIES IN THOSE CONDITIONS? Cell is a Crowded system : mostly interphases Hypothesis: The self association implies organization of Functional nanostructures of water at membranes interphases specific for membrane response. Water and Membranes: from the experiment to simulation
WATER ENVIRONMENTS IN CELL DIMENSION THE MEMBRANE INTERPHASES 1 nm thickness with 20 water molecules per lipid 10-50 mm RESTRICTED ENVIRONMENTS Water and Membranes: from the experiment to simulation
RESTRICTED ENVIRONMENTS : SURFACE TENSION Losse of tetrahedral array Residual forces
RESIDUAL FORCES (SURFACE TENSION) IS REDUCED BY THE STALIZATION OF LIPID IN A MONOLAYER AT THE AIR WATER INTERFACE -dg/lnc = RT G Surface excess G = n/A p = go - g
THERMODYNAMIC PROPERTIES Surface free energy = surface tension changes Propensity of biomembranes to response to molecular events, such as aminoacid or peptides. Water nanodomains as molecular anthena
Balance with Wilhelmy plate Barrier Barrier Monolayer Trough with subphase Flux of Water Coefficient of interaction water-water AreaVariation
Surface pressure- area isotherms Balance with Wilhelmy plate Barrier Barrier Monolayer Collapse Trough with subphase Solid phase Condensed Liquid (CL) Expanded Liquid (EL) ( EL + CL ) Gas phase phases coexistence
RESPONSIVE MEMBRANES DMPC = 12-20 water /lipid DMPE = 2-6 water /lipid DMPE DMPC
SURFACE TENSION INCREASE PRODUCED BY EXPANSION INCREASES PROPENSITY TO ADSORB EFFECTORS DMPC Different lipid head groups response is similar while chain is maintained. Increase of area means increase of water beyond hydration shell (confined water). R E S P O N S E DMPE Surface tension: Increase in area per lipid
Hydration water depends on chemical structure of lipid head groups
Collapse Condensed Liquid (CL) Expanded Liquid (EL) Solid phase Response of membranesdepends differently tomembranetensionaccording to acylchain composition
Two kinds of water : hydration and confined water. • Domains of confined water appear beyond the hard core hydration shell of lipids making membrane responsive. • Confined water determines the surface free energy of lipid interphases • Confined water domains appear to be modified by lateral pressure. hydration water (critical packing) Non responsive membrane confined water Responsive membrane Water in compression Water out
STRUCTURAL PROPERTIES OF WATER INTERPHASE BY FTIR SPECTROSCOPY
FTIR SPECTRA REPORTS RELATION BETWEEN CH2 CONNECTED AND ISOLATED POPULATIONS Disalvo et al. BBActa 1828 (2013) 1683–1689
water activity Connected populations Confined water may occupy regions between isolated CH2 populations IsolatedPopulations
WATER STATE AROUND CONNECTED AND ISOLATED CH2 POPULATIONS
APPARENT WATER CHEMICAL POTENTIAL AND ISOLATED METHYLENE GROUPS Chemical Potential of Confined Water in the membrane Isolated Methylenes Populations
WATER DISTRIBUTION IN MEMBRANE GROUPS IN COMPRESSED (BLACK)\ AND EXPANDED (GRAY) MEMBRANES
56% 44% 45% 55% EFFECT ON CARBONYL GROUPS 48% 52% 45% 55%
Labile hydration-water molecules expected to be displaced from binding sites. The replacement of so-called ``unfavorable'' water molecules by groups of aminoacids is a principal driving force for binding and membrane response. g = nsw (mows - mo) The interface is a bidimensional solution of hydrated polar groups and confind water. Confined water determines the chemical potential of water that drives the response of the membrane to biological effectors Bidimensional Solution Of Hydrated Head Groups(Defay & Prigogine 1966; Evans & Skalak, 1978)
Thermodynamic and structural link A variety of water populations
Waterons (basedonchanges in themultiplewaterpopulations in thelipidinterphasewithdifferent free energycontent) WCP
Nature has provided a great diversity of lipids. Lipids organize water. Lipid head groups protrude from the membrane phase promoting different water organization. Head groups hydration is determined for cellular species. Chain structure which is linked to growing conditions (diet, temperature, hydric stress, oxidative stress) determines confined water. LIPIDOMICS MEETS AQUAOMICS.
CONCLUSIONS Confined water: Chain dynamics is the backbone in which hydrogen bond dynamic propensity. It is a relevant tool for membrane response to different aminoacid motifs. Confined water may be the common intermediary in the interaction of different proteins, peptides or aminocids with lipid membranes Waterons are the water molecules exhibiting an enhanced propensity to be displaced upon aminoacid association resulting in a stability gain. Dehydration propensity is specific for some aminoacid motifs. The work implied in water removal is connected to the binding-carbonyl hydration properties by means of water density fluctuations. .
Laboratory of Biointerphases and Biomimetic Systems, CIBAAL (FAyA-FCEyT, UNSE-CONICET) Santiago del Estero, Argentina. ANIBAL DISALVO MARIA DE LOS A. FRIAS AXEL HOLLMANN ANDREA CUTRO SEBASTIAN ROSA LUCIA LAVAISSE PABLO SAIN LAURA LEMOS M. JOSE TISSERA ANAHI SORIA JIMENA CEJAS PATRICIA MATURANA PABLO ARGANARAZ Alejandro Pinto, INBIONATEC Gustavo Appignanessi, Laureano Alarcon INQUISUR