Abstract

Denaturation Of Lysozyme In Aqueous Urea And Degree Of Exposure

Author(s): Someswar Chatterjee, I.Basumallick

Free energies of transfer (Gt) of Lysozyme (LZ) from water to aqueous solutions of urea (4M, 6Mand 8M), a protein denaturing solvent have been dissected into cavity term [Gt(cav)] and interaction term [Gt(int)]. The interaction free energy includes all types interactions like hard-soft, hydrogen bonding, electrostatic etc. The cavity forming free energies have been calculated using standard version of scaled particle theory (SPT) with well reported SPT parameters. It has been found that transfer free energies of cavity formation Gt(cav) for Lysozyme from water to urea-water are unfovourable whereas the transfer free energies of interaction Gt(int) are favourable. These results are in conformity with the reported values for the transfer ofRibonucleaseAfromwater to urea-water.Anewapproach for the calculation of degree of unfolding has been proposed.