Influence of heating on the activity of α-mannosidase

Abstract

The influence of heating on the activity of Jack bean α-mannosidase has been studied. The aged enzyme (3 years in concentrated commercial solution) has been stored at 4 ̊ C for 5 days in acetic acid/sodium acetate buffer (pH=5) with no added ions or albumin. The enzyme has been heated for various amounts of time (5 min, 10 min, 20 min, 30 min) at different temperatures (50 ̊C, 60 ̊C, 70 ̊C, 75 ̊C), then it was cooled and assayed at 20 ̊C. The residual enzyme activity has been calculated. After 5 minutes of heating at 50 ̊ C, the enzyme retained 65 % of activity but is almost completely inactivated when heated for 5 minutes at 70 ̊C.