小菜蛾酪氨酸酶生物化学性质研究  

Biochemical characteristics of tyrosinase in the diamondback moth, Plutella xylostella(L.)

作　　者：梁沛[1] 孟凤霞[1] 高希武[1] 郑炳宗[1] 程刚[1] 

机构地区：[1]中国农业大学昆虫学系,北京100094

出　　处：《昆虫学报》2003年第5期553-557,共5页Acta Entomologica Sinica

基　　金：国家重大基础研究"973"项目 (G2 0 0 0 0 162 0 7)

摘　　要：采用时间动力学法对小菜蛾Plutellaxylostella酪氨酸酶的最适反应条件、对抑制剂的敏感度以及发育期变化规律进行了研究。结果表明 :小菜蛾酪氨酸酶反应的最适pH值为 6 4 ,反应线性时间为 0～ 2min ,在 2 2℃和 4℃下其活性分别可保持 12h和 72h ,在 - 2 0℃下至少可保持 7天。不同发育阶段小菜蛾酪氨酸酶活性的大小依次为预蛹 >4龄幼虫 >蛹 >1龄、2龄、 3龄幼虫 >成虫。苯基硫脲 (phenylthiourea ,PTU)对小菜蛾阿维菌素抗性品系和敏感品系酪氨酸酶活性的抑制中浓度 (I50 )值分别为 1 1796 μmol L和 1 2 795 μmol L 。The optimum reaction conditions, sensitivity to the inhibitor and the developmental changes of tyrosinase in the diamondback moth, Plutella xylostella (L.), were studied using time-driving dynamic method. The results showed that the optimum pH of tyrosinase is about 6.4; The OD 420 values are linear with time from 0-2?min. When stored at 22℃ and 4℃, the prepared tyrosinase could keep its best activity for 12?h and 72?h, respectively; and while stored at -20℃, the tyrosinase could keep its activity for at least 7 days. The activity of tyrosinase in different developmental stages of P. xylostella follows the order pharate pupa>4th instar larvae >pupa>1st-3rd instar larvae > adult. The I 50 of phenyl thiourea (PTU) to the activity of tyrosinase from both the resistant and susceptible strains showed no obvious difference (1.1796?μmol/L and 1.2795?μmol/L, respectively).

关 键 词：小菜蛾 酪氨酸酶 生物化学性质 

分 类 号：Q965.9[生物学—昆虫学]