Pressure Stability of Proteins at their Isoelectric Points

Yeast alcohol dehydrogenase is slowly denatured at moderate hydrostatic pressure (t1 / 2 ? 30 min at 2 kbar and pH 7). The extent of denaturation is pH dependent with maximal stability near the isoelectric point of the protein, pH = 5.4. While not a surprising finding, it appears that this phenomenon has not been documented before (or at least not identified) despite many investigations into the pressure stability of proteins. Consideration of changes in the net charge of proteins far from their isoelectric points may explain other pressure effects as well.