棕榈酰化超氧化物歧化酶的制备及性质研究

为了增强超氧化物歧化酶的稳定性，用棕榈酸对其进行了修饰，在修饰条件下，酶分子表面氨基修饰率为55％时，酶的活力回收为63％。修饰后的酶在耐热、耐酸、耐碱、抗有机溶剂变性和抗蛋白水解能力上均高于天然超氧化物歧化酶，为将超氧化物歧化酶作成实用药物和进一步扩大其应用范围创造了条件。

Preparation and property of palmitoyl modified SOD

Almost 3% to 10% of the oxygen utilized by tissues is converted to its reactive intermediates known as reactive oxygen species (ROS) , such as superoxide radicals, hydroxyl radicals and so on, which would impair the functioning of cells and tissues, causing various diseases. Superoxide dismutase (SOD) catalyzes the conversion of single electron reduced species of molecular oxygen to hydrogen peroxide and oxygen. Thus, SOD possesses important physiological significance. However, native SOD is sensitive to many factors, such as heat, extreme pH, proteases, inhibitors and organic solvents etc. and its stability is not good. In order to enhance its stability palmic acid was used to modify SOD. Activated palmic acids can react with the NH2 groups on the surface of the enzyme. In the experiments, the enzyme activity recovery reached 63% when the amino groups were modified up to 55 % . The thermostability and the ability to resist acid, alkaline, protease and organic solvents for the palmitoyl modified enzyme were remarkably increased, implying that the palmitoyl modified SOD has a great potential in medicine, cosmetics and fine chemical production.