EQUILIBRIUM ADSORPTION OF POLAR-MOLECULES ON PROTEINS AS A SURFACE-RECONSTRUCTION PROCESS

The problem of protein folding-unfolding is age-old and not fully solv ed yet. An amino acid sequence alone is insufficient to specify comple tely the local configuration, because nonspecific long-range forces te nd to impart to the protein a different structure from what would resu lt from covalent bonds only. The adsorption of polar molecules on prot eins involves an energy of the same order as the one which stabilizes the native configuration, so that the solvation resulting from the ads orption is expected to modify progressively the protein configuration. The surface-reconstruction model proposed by Landsberg for the Elovic h adsorption kinetics is modified to describe the adsorption equilibri um on reconstructable surfaces. In this model adsorption produces a pr ogressive exposure of the protein skeleton to the atmosphere. The mode l can be worked to account for denaturation and the formation of the m olten globule.