Thermo-acoustical and Taste Behavior Studies on Interionic Interactions of Lhistidine in Aqueous Maltose Solutions at Varying Mass Percentages and Different Temperatures

Thermodynamic parameter, like volumetric and acoustical properties, provides valuableinformation regarding solute-solute, solute-solvent and solvent-solvent interactions. It is wellknown that saccharides are typical nonelectrolytes with several hydroxyl groups and these polyhydroxy compounds help in stabilizing the native conformations of globular proteins [1-4].Apparent molar volumes, V and adiabatic compressibilities, s, K of L-histidine in theconcentration range (0.0 to 0.18 mol kg-1) in aqueous maltose solutions ranging from pure waterto 20.0 mass % of maltose have been determined at 298.15, 303.15, 308.15 and 313.15 K fromprecise measurements of density and speed of sound. Apparent molar volumes (  V ) andapparent molar adiabatic compressibilities ( K s,  ) of L-histidine at infinite dilution have beenevaluated. Transfer volumes (  V tr  ) and transfer adiabatic compressibilities ( tr s, K  ) atinfinite dilution from water to aqueous maltose solutions have been also calculated. Transferparameters have been interpreted in terms of solute-cosolute interactions on the basis ofcosphere overlap model. Interaction between saccharides and proteins molecules is expected tocreate polar environment, which helps to increase the hydrophobic interactions in proteins, thusstabilizing the protein. It has been observed that there exist strong solute–solvent interactions inthese systems, which increase with increase in maltose concentration.

Keywords:

L-histidine , Maltose , Density , Speed of Sound , Apparent Molar Volumes , Adiabatic Compressibilities , Taste Behavior