Protease mediated prophenoloxidase activation in the hemolymph of the tobacco hornworm, Manduca sexta
Protease mediated prophenoloxidase activation in the hemolymph of the tobacco hornworm, Manduca sexta
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烟草天蛾血淋巴中蛋白酶介导的酚氧化酶原激活
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
M. Sugumaran
中科院分区：
文献类型：
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作者：
S. Saul;M. Sugumaran
内毒素和海带多糖激活六爪金龟血淋巴中的酚氧化酶原。二异丙基氟磷酸盐抑制了这种激活，这表明激活级联中存在丝氨酸蛋白酶。外源添加的蛋白酶，如链霉蛋白酶、胰凝乳酶、枯草杆菌酶和热裂解酶，也能激活Manduca血浆中的酚氧化酶原。然而，这些酶没有引起任何可检测到的部分纯化的酚氧化酶原的激活。热裂解酶和枯草杆菌菌素介导的酚氧化酶原的激活被对硝基苯基对氨基苯甲酸酯抑制。同样地，苯甲双胺抑制了热裂解酶催化的酚氧化酶原的激活。活性测量显示，在酚氧化酶原激活之前，丝氨酸蛋白酶被激活。这些结果表明，丝氨酸蛋白酶的前体形式的存在，负责原酚氧化酶的激活在六分之鱼血淋巴。
Endotoxin and laminarin activated prophenoloxidase in the plasma of Manduca sexta hemolymph. Diisopropylfluorophosphate inhibited this activation, suggesting the presence of a serine protease in the activation cascade. Exogenously added proteases such as pronase, chymotrypsin, subtilisin, and thermolysin also activated prophenoloxidase in Manduca plasma. However, these enzymes did not cause any detectable activation of partially purified prophenoloxidase. Thermolysin and subtilisin mediated activation of prophenoloxidase was inhibited by p-nitrophenyl-p′-guanidobenzoate. Similarly, benzamidine inhibited prophenoloxidase activation catalyzed by thermolysin. Activity measurements reveal the activation of a serine protease prior to prophenoloxidase activation. These results indicate the presence of a precursor form for the serine protease which is responsible for prophenoloxidase activation in Manduca sexta hemolymph.