南美白对虾血细胞酚氧化酶活力的研究

A Study on the Phenoloxidase Activities in Homocytes of Penaeus Vannamei

研究了凡纳滨对虾(Penaeus vannamei)血细胞酚氧化酶在不同温度、pH及在一定浓度的Ca2+和SDS下酶活力的变化情况.试验结果表明:在自然状态下,南美白对虾血淋巴中的血细胞内存在酚氧化酶,但更多的是以酶原的形式存在于血细胞内,不显活性;Ca2+、SDS能激活酚氧化酶原,提高PO活力;在一定范围内改变pH值,或提高温度也能够提高酶活力.该酶的最适pH值为6.0,最适作用温度为50℃.

Hoemolymph of shrimp is extracted from Penaeus vannamei and some of its characteristics are studied. The results of the study show that in natural situation Penaeus vannamei hemocytes have phenoloxidase（PO） which exists most in the form of prophenoxidase（proPO） without activity. SDS and Ca^2＋ can activate prophenoxidase（proPO）. In certain range, the change of pH and temperature may increase phenoloxidase（PO） activity. The optimum pH of Penaeus vannamei phenoloxidase（PO） is 6.0. The optimum temperature of Penaeus vannamei phenoloxidase（PO） is 50℃.