长效重组人超氧化物歧化酶的研制及其辐射防护作用研究

INVESTIGATION OF THE PREPARATION OF LONG HALF-LIFE RECOMBINENT HUMAN SUPEROXIDE DISMUTASE AND ITS RADIOPROTECTIVE EFFECT

选用无毒、无免疫原性的高分子化合物聚乙二醇（ＰＥＧ）为修饰剂，以活性酯法制备出ＰＥＧ－重组人超氧化物歧化酶（ＰＥＧ－ｒｈＳＯＤ）共价结合物。修饰酶的生物半衰期为１５ｈ，比修饰前延长了９０倍，对酸、硷、热的耐受力明显高于修饰前。用照射小鼠活存率评价了ＰＥＧ－ｒｈＳＯＤ的辐射防护作用。小鼠受８．５Ｇｖｒ射线照射前１ｈ腹腔注射３０万Ｕ／ｋｇＰＥＧ－ｒｈＳＯＤ，可提高活存率４２％，与未修饰的ｒｈＳＯＤ相比，活存率提高１４％。

ecombinent humtan Cu/ZnSOD(rhCu/ZnSOD)was covalently linked with activated polyethylene glycol(PEG),a kind of nontoxic,nonimmunogenic and biocompatible polymer,The modified enzyme,PEG-rhCu/ZnSOD,has longer half-life(15h).Its abilitie:to resist acid,alkali and heat were increased significantly.Mice given PEG-rhCu/ZnSOD 1h bcfore irradiation had higher survival rate than those not given or given rhCu/ZnSOD after they were exposed to whole body Y-ray irradiation at dose of 8。5Gy。