title: Cloning, expression, and characterization of prophenoloxidase from Antheraea pernyi.
abstract: Prophenoloxidase (PPO) is an essential enzyme in insect innate immunity because of its role in humoral defense. In this study, we have cloned a full-length cDNA of Antheraea pernyi prophenoloxidase (ApPPO) with an open-reading frame encoding 683 amino acids, and the deduced amino acid sequence of ApPPO exhibited a high similarity with those of lepidoptera. The expression of ApPPO was inducible so that the mRNA level was significantly upregulated in the microbial challenged tissues, including fat body, hemocytes, and midgut. To better investigate the enzymatic and immunological properties of ApPPO, recombinant ApPPO (rApPPO) was produced in Escherichia coli. Several functional verification experiments were performed after studying the enzymatic properties. It was found that rApPPO could be stimulated by the microbial challenged larvae hemolymph and then killed bacteria in the radial diffusion assay. Furthermore, rApPPO also induced the transcription of cecropins after injected into the larvae 24 h later.
authors.affiliation: School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, P. R. China; Benxi Institute of Medicines, Shenyang Pharmaceutical University, Benxi, Liaoning Province, P. R. China.
authors.forename: Wang Xia
authors.initials: WX
authors.lastname: Lu
authors.forename: Du
authors.initials: D
authors.lastname: Yue
authors.forename: Zhang Jing
authors.initials: ZJ
authors.lastname: Hai
authors.forename: Wen
authors.initials: W
authors.lastname: Daihua
authors.forename: Zhao Ming
authors.initials: ZM
authors.lastname: Yi
authors.forename: Wu Chun
authors.initials: WC
authors.lastname: Fu
authors.forename: Zhang
authors.initials: Z
authors.lastname: Rong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004156:Catechol Oxidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D054807:Cecropins / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004792:Enzyme Precursors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006458:Hemolymph / Q000276:immunology; D007814:Larva / Q000276:immunology / Q000382:microbiology; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D054807:Cecropins; D018076:DNA, Complementary; D004792:Enzyme Precursors; D012333:RNA, Messenger; C038451:pro-phenoloxidase; D004156:Catechol Oxidase
keywords: Antheraea pernyi; PPO-activating system; innate immunity; prophenoloxidase (PPO)