亚洲玉米螟血淋巴中酚氧化酶的研究

酚氧化酶(Phenoloxidase,简称PO)大量存在于亚洲玉米螟(Ostrinia furnacalis)幼虫的血浆中,血细胞中甚少.该酶的活力与幼虫的发育期相关,在蜕皮和化蛹前后活力达高峰.PO可以粘附在酵母菌细胞表面,但未发现具有调理作用.以Sephadex G-200层析,对PO进行了部分纯化,比活力可提高56倍.试虫感染酵母菌后,活体内血浆PO活力即刻下降;体外证明,感染血浆可抑制正常血浆PO活力,以胰蛋白酶和昆布多糖测试以及行耐温实验,表明该抑制物为蛋白质性质.对PO的防卫作用进行了简要的讨论.

STUDIES ON THE PHENOLOXIDASE IN THE HEMOLYMPH OF THE ASIAN CORNBORER OSTRINIA FURNACALIS

The result of experiments on the Asian comborer Ostrinia jurnacalis indicated that the hemolymph plasma contained a large amount of phenoloxidase (PO), but a little PO was present in the hemocytes. The PO activity in the hemolymph fluctuated with the developmental stage of the larva; it reached the maximal levels before molt and pupation. Thise enzyme was found able to attach to the fungal cell wall, but it showed no opsonic capacity The plasma PO was partially purified by Sephadex G-200 chromatography and its activity was increased 56 folds. After the larva was infected with yeast cells the plasma PO activity would drop to a minimal level. The plasma of the infected larva could inhibit the PO activity of normal plasma in vitro. It was demonstrated that the inhibitory factor may be a protein. The defensive effect of PO in immunity is discussed.