Retention and Thermodynamic Properties of Three Insulin Variants on the Reversed-phase Liquid Chromatography

The retention and thermodynamic behaviour of three insulin variants, bovine, human and porcine insulins, in reversed-phase high-performance liquid chromatography were studied over a range of temperatures between 10 and 65 degrees and a range of methanol concentrations between 53 and 59%(v/v). The results demonstrated that the slight difference of three insulins in the amino acid sequence could be resolved significantly in C(8)-hydrophobic ligand. Values for the relative changes in enthalpy (deltaH deg;/R) and entropy (deltaS deg;*) associated with the interaction process were also determined. These values of thermodynamic parameters would provide further insight into the factors involved in the stabilization of protein conformation and the mechanism of the interaction of peptides with hydrophobic surfaces. The experimental results also demonstrated that the determination of thermodynamic parameters of interactions between peptides and hydrophobic surfaces would provide an alternative approach for the investigation of mechanisms of protein folding and of interaction between proteins.