Trehalose-mediated protection of the plasma membrane H+-ATPase from Kluyveromyces lactis during freeze-drying and rehydration.

The protective efficiency of carbohydrates was as follows: trehalose higher than maltose higher than sucrose higher than glucose higher than galactose. Each carbohydrate exhibited the maximal protection at a concentration of 20 milligrams carbohydrate per milligram of protein or above. Trehalose, at 20 milligrams/milligram protein, protected the enzyme activity completely during freeze-drying and rehydration. Rehydration temperature was critical; at 20 deg C or below, activity was fully retained, while at 30, 40, or 50 deg C activity decreased in proportion with temperature. Storage at 4 deg C resulted in retention of most of the enzymatic activity for 60 days. The protection of the H+-ATPase by trehalose suggests that this carbohydrate might protect other membrane enzymes from inactivation during handling.