棉铃虫感染中华卵索线虫后血淋巴酚氧化酶活性的变化及其分离纯化

Activity changes of phenoloxidase in haemolymph of Helicoverpa armigera parasitized by Ovomermis sinensis and its purification

研究了中华卵索线虫Ovomermis sinensis感染棉铃虫Helicoverpa armigera幼虫后宿主体内酚氧化酶活性的变化。研究结果表明,在感染后的第1天,中华卵索线虫的侵入引起酚氧化酶活性的增加,感染组酶活性是同期对照组的1.12倍;但在随后的寄生期间,中华卵索线虫抑制了宿主的酚氧化酶活性,其中以第5天的抑制最为强烈:同期对照组酶活性是感染组的1.52倍。对酚氧化酶进行了初步的分离纯化,纯化倍数为41.5倍,酶得率为12.7 %,比活力为4 030.6 U/mg。

The activity changes of phenoloxidase in haemolymph of Helicoverpa armigera larvae parasitized by Ovomermis sinensis were investigated. The results showed that on the first day of infection, the phenoloxidase activity of the infected group increased, which was 1.12 times that of the control group; but in the latter time of infection, the phenoloxidase activity of the infected group was inhibited by the nematodes. On the fifth day of infection, the inhibition reached the highest degree, and the phenoloxidase activity of control group was 1.52 times that of the infected group. Purified with 40% saturated （NH4）2SO4 and Sephadex G-200 gel filtration from the crude enzyme, the phenoloxidase with the purification factor of 41.5, the yield factor of 12.7% and the specific activity of 4 030.6 U/mg was obtained.