Einfluß verschiedener Zucker auf die Hitzestabilität von Enzymen

Addition of sugar influences the thermal stability of oxidoreductases. Horseradish peroxidase, lactoperoxidase and lipoxidase I from soybeans were investigated. Non reducing sugars like sucrose and trehalose prevent the investigated enzymes from heat denaturation. Maltose and lactose, two disaccharides with a 1,4-linkage, which still contain an aldehyd group for reduction reactions, however show destabilizing effects. Addition of glucose leads to an increased denaturation rate in all investigated examples. Xylit, a sugar alcohol, shows no effect. Only in very high concentrations (60%) enzyme stabilization can be observed. The effects of the investigated sugars on thermal-denaturation correlates with the redox potential of their solutions.