Thermodynamic Contribution of Amino Acids in Ionic Liquids Towards Protein Stability

Title:Thermodynamic Contribution of Amino Acids in Ionic Liquids Towards Protein Stability

Volume: 1 Issue: 2

Author(s): Awanish Kumar, Pannuru Venkatesu, Mohamed Taha and Ming-Jer Lee

Affiliation:

Keywords: Amino acids, free energy, ionic liquids, molecular dynamics, protein stability, thermodynamics.

Abstract: Amino acids (AA_s) combine to form a three-dimensional protein structure and are of very much importance in understanding the biophysical properties of biomolecules. Basically, the nature and the arrangement of the AA_s in a protein backbone is only responsible for the individual characteristics of the macromolecule. The AA_s in a protein backbone are influenced by the solvent molecules hence, it is very important to have a clear idea on the solubility, stability, and thermodynamic properties of these AA_s in various solvents and co-solvents. A basic level of quantifying protein-solvent interactions involve the use of transfer free energies, ΔG_tr from water to solvents. The values of ΔG_tr for side chains and peptide backbone quantify the thermodynamic consequences of solvating a protein species in a co-solvent solution relative to pure water. Based on the transfer model and experimental ΔG_tr for these AA_s, it has been proposed that these cosolvents exert their effect on protein stability primarily via the protein backbone. The ΔG_tr of AA_s from water to another solvent system will be either favorable or unfavorable. By definition, an unfavorable transfer free energy, ΔG_tr > 0, means that the protein becomes solvophobic on transfer to a solvent, whereas a favorable transfer free energy, ΔG_tr < 0, represents that the protein becomes solvophilic on transfer to a solvent. The sign and magnitude of the measured ΔG_tr quantifies the protein response to changes in solvent quality. Therefore, this review will provide the basis of a universal mechanism for co-solvent-mediated (that includes the new novel biocompatible ionic liquids (ILs)) protein stabilization and destabilization as the protein backbone is shared by all proteins, regardless of side chain sequence.

Cite this article as:

Kumar Awanish, Venkatesu Pannuru, Taha Mohamed and Lee Ming-Jer, Thermodynamic Contribution of Amino Acids in Ionic Liquids Towards Protein Stability, Current Biochemical Engineering (Discontinued) 2014; 1 (2) . https://dx.doi.org/10.2174/2212711901666131224222431