Thermodynamics Properties of Leucine and Isoleucine Peptides in Water.

Thermodynamic properties of amino acids explore the ideas about the energetic contribution in biomolecular interfaces. In our work, we have estimated the solvation free energy of leucine and isoleucine peptides with the variation of chain length or residues of different monomer units (n=1, 2, 4, 8 & 16) using molecular dynamic simulation. We modeled our system using OPLS-AA force field and TIP3P water model at 310 K temperature. Solvation free energy of both leucine and isoleucine peptides increases with increase in chain length, which have been reported by using TI, TI-CUBIC and BAR methods. The increase in solvation free energy with increase in chain length of both peptides is also supported by the increase in hydrogen bond and solvent accessible surface area (SASA) with the number of residues.