酚氧化酶原激活酶（prophenoloxidase activating enzyme, PPAE）是酚氧化酶激活系统（prophenoloxidase activating system, PPOAS）的组成部分，是无脊椎动物抵御入侵微生物的关键酶。本研究利用RACE技术从柑橘全爪螨Panonychus citri (McGergor)体内获得一条PPAE基因全长cDNA，命名为PcPPAE (GenBank：KC136292)，属于丝氨酸蛋白酶家族。该基因cDNA全长1 676 bp，开放阅读框1 377 bp，编码458个氨基酸。该基因编码蛋白预测分子量为499 ku，理论等电点（pI值）为568，分子式为C2201H3467N607O678S22，不稳定系数为4151，总亲水性系数为-0268。经序列比对发现该基因具有发夹结构域，丝氨酸蛋白酶结构域，以及丝氨酸蛋白酶结构域中保守的催化三联体。系统发育分析表明该基因与二斑叶螨发夹结构丝氨酸蛋白酶基因的亲缘关系最近。本研究首次从柑橘全爪螨体内克隆获得酚氧化酶原激活酶，为后期进行柑橘全爪螨抵御微生物侵染机制研究奠定了基础。

Prophenoloxidase, a member of the serine proteinase group, is a key enzyme in invertebrates for defense against microbial infections and the prophenoloxidase activating enzyme (PPAE) is an important component of the prophenoloxidase activating system (PPOAS). A fulllength cDNA of the PPAE gene named PcPPAE (GenBank: KC136292) was cloned from Panonychus citri (McGregor) using rapid amplification of cDNA ends (RACE). The cloned gene was 1 676 bp in length with an ORF of 1 377 bp encoding 458 amino acid residues. The protein predicted from the cloned PcPPAE had a molecular weight of 49.9 ku and a theoretical isoeletric point (pI) of 5.68. Its predicted molecular formula was C2201H3467N607O678S22. Bioinformatic analysis showed that its instability index was 41.51 and its GRAVY was -0.268. The deduced protein PcPPAE had a clipdomain, serine proteinase domain and a conserved catalytic triad in the serine protease domain. Phylogenetic analysis indicates that PcPPAE is most closely related to the clipdomain serine proteinase of Tetranychus urticae (Koch). These results provide the basis for further research on defense against microbial infection in the citrus red mite.