Thermodynamic Analysis of Lysozyme Denaturation by Surfactants

摘要: Spectroscopic techniques (UV absorption, fluorescence and circular dichroism) are applied for probing the conformational stability of lysozyme as a model protein after impact surfactants. The investigations allow equilibrium constant, K, free energy change, ΔG, transition from folded (native) to unfolded (denatured) state be estimated. ΔG at 25 °C in absence additives allows quantifying protein. Though results based on validity several assumptions regarding folding/unfolding mechanism, evaluation procedure, environmental conditions, thermodynamics surfactant-induced unfolding may Compared induced by chaotropic denaturant guanidinium chloride, cationic zwitterionic surfactants found yield lower values. In case lysozyme, anionic nonionic did not result curves. interpretation curves indicated existence two-state behavior. Quantities which do significantly depend such midpoints concentrations thermal curves, c 1/2 T m, also comparing stabilities proteins, even irreversible transitions. denaturation derivation enthalpy entropy changes, ΔH ΔS.