【摘要】 采用酶活性测定及双扩散法研究了蒜酶及修饰度为 5 3%的多聚乙二醇 (PEG)化蒜酶的某些理化性质、抗原性和免疫原性及在体外和小鼠体内的活性半衰期。结果显示 :在 75 %的乙醇中 ,蒜酶完全失活 ,而 PEG化蒜酶仍保持了 5 0 %的活性。蒜酶和 PEG化蒜酶最适温度均为 40℃。与蒜酶相比 ,PEG化蒜酶在更宽的 p H范围内具有催化活性 ,蒜酶的最适 p H为 7,而 PEG化蒜酶在 p H为 6～ 7范围内均具有最强的催化活性。蒜酶与其抗血清形成明显沉淀线 ,而PEG化蒜酶既不与蒜酶的抗血清也不与自身的抗血清形成沉淀。在血清中 PEG化蒜酶的半衰期为 90 h,是蒜酶的 45倍。PEG化蒜酶的小鼠体内半衰期达 2 .5 8d,而蒜酶在小鼠体内 30 min后 ,已测不出催化活性。多次应用 PEG化蒜酶的小鼠体内 ,相邻两次应用的 PEG化蒜酶半衰期无显著性差异。更多还原

【Abstract】 The physical, chemical, immunological characters and half life in vitro or in vivo of alliinase and alliinase modified with polyethylene glycol (PEG) in 53 % modification degree were studied. Native enzyme lost its activity completely in 75% of ethanol, while modified enzyme retained 50% of relative activity. Modified enzyme and native enzyme reached the highest activity at 40 ℃. Comparing with native enzyme, modified enzyme had activity in a broader range of pH. The optimal pH value of native enzyme was 7, while that of modified enzyme was from 6 to 7. Double diffusion test showed that native enzyme formed an obvious sedimentary thread with antigen, however, modified enzyme didn’t react either with the antiserum of native enzyme or with itself antiserum. In serum, the half life of modified enzyme was 90 h, 45 times of native enzyme’s. The half life of modified enzyme in mice was 2.58 d, while native enzyme’s less than 30 min. After PEGlyated alliinase was used several times in mice, no significant difference of half life could be found between neighboring two doses in succession.更多还原