Drosophila melanogaster prophenoloxidases respond inconsistently to Cu2+ and have different activity in vitro
Drosophila melanogaster prophenoloxidases respond inconsistently to Cu2+ and have different activity in vitro
复制标题
果蝇酚氧化酶原对 Cu2+ 的反应不一致，并且在体外具有不同的活性
DOI：
10.1016/j.dci.2011.12.001
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发表时间：
2012-03-01
影响因子：
2.9
通讯作者：
Ling, Erjun
中科院分区：
文献类型：
--
作者：
Liu, Fei;Chen, Yang;Ling, Erjun
双翅目昆虫和蚊子一样，拥有两个以上的酚氧化酶原(PPO)基因，但目前尚不清楚它们的基因产物在生化特性和生理功能上是否存在差异。在这里，我们以三种果蝇PPO为模型，通过在S2细胞中的表达来研究它们的性质。我们的数据显示，PPO以乙醇可激活的构象表达：rPPO1和rPPO2需要在培养基中加入额外的Cu2+，而rPPO3不需要。RPPO1在几分钟内与Cu2+结合；当Cu2+浓度较高时，rPPO2在数小时内完成这一作用。因此，rPPO1和rPPO2在Cu2+结合后以apo-rPPO的形式表达，rPPO3在表达后立即成为holo-PPO。令人惊讶的是，在没有乙醇的情况下，表面上完整的rPPO3催化了多巴胺的氧化和黑化。本文所描述的在S2细胞中成功表达rPPO的方法为我们未来研究小昆虫类蚊子中特定的PPO基因的特性提供了机会。(C)2011爱思唯尔有限公司。保留所有权利。
Dipteran insects, like mosquitoes, possess more than two prophenoloxidase (PPO) genes, but it is unclear whether their gene products differ in biochemical properties and physiological functions. Here, we used three Drosophila melanogaster PPOs as models to study their properties through expression in S2 cells. Our data revealed that the PPOs were expressed in the ethanol-activatable conformation: rPPO1 and rPPO2 needed additional Cu2+ in the medium, but rPPO3 did not. rPPO1 bound Cu2+ within minutes; rPPO2 did that in hours when Cu2+ were present at a higher concentration. Thus, rPPO1 and rPPO2 were expressed as apo-rPPO and became holo-PPO upon Cu2+ binding; rPPO3 was holo-PPO immediately after expression. Surprisingly, in the absence of ethanol, the apparently intact rPPO3 catalyzed dopamine oxidation and melanization. The successful method for rPPO expression in S2 cells described in this paper will provide us with an opportunity to study the properties of a specific PPO gene in a small insect like mosquitoes in the future. (c) 2011 Elsevier Ltd. All rights reserved.