Abstract

Isozymes of yeast alcohol dehydrogenase are slowly denatured at moderate hydrostatic pressures ( < 3 kbar). The time courses for inactivation are biphasic and both phases of both isozymes are protected by trehalose. ADH-I is slightly more barostable than ADH-II which is opposite to their thermostabilities. Trehalose at 1M extends their halflives about 6-fold at 2 kbar, pH 7.5 and 25°C. In contrast, 1M sucrose provides only 4.4-fold protection under identical conditions, a finding consistent with the superior protein stabilization of trehalose to other denaturants.

Keywords: yeast alcohol dehydrogenase, trehalose, hydrostatic pressure, protein denaturation, barostability, thermostability, surface tension