Slab Gel Electrophoresis Performed at High Hydrostatic Pressure: A New Approach for the Study of Oligomeric Proteins

In the last few years several studies have demonstrated the reversible dissociation of oligomeric proteins under pressure (for review see: Heremans, 1982; Weber and Drickamer, 1983). The dissociating effects of pressure are generally ascribed to the intersubunit surfaces and the restrictive effect of the covalent bond architecture of the protein. The pressure dissociation has been detected either by indirect or direct methods. Indirect methods, such as hybridization studies (Jaenicke and Koberstein, 1971) and activity measurements (Penniston, 1971; Schade et al., 1980; Seifert et al., 1985) have been employed with some success. These indirect methods are valuable in revealing qualitatively the involvement of protein dissociation in the observed effect of pressure. However, the stoichiometry of dissociation and the thermodynamic parameters (volume change and dissociation constant) cannot be unambiguously determined. Methods which directly reveal the state of association are more suitable for a thermodynamic approach to the pressure dissociation, although they are not immune to experimental problems.