title: Detection and characterization of phenoloxidase in the freshwater planarian Dugesia japonica.
abstract: Freshwater planarians have traditionally been favored animal models in regenerative and developmental biology. Little is known about the immunological research in these animals. Here, we provide spectrophotometric, electrophoretic and histochemical evidence demonstrating the presence and characterization of phenoloxidase (EC 1.14.18.1; PO) activity in the planaria Dugenia japonica. PO activity was optimal at pH 7.5 and at a temperature of 45 degrees C. ProPO in the humoral fluid was readily activated by trypsin and zymosan, and was susceptible to phenylthiourea. Two bands of PO activity in the humoral fluid with 150 and 300 kDa by native PAGE and a single band with 150 kDa after SDS-PAGE were resolved. Enzyme histochemical staining demonstrated the presence of PO in the epidermal cell and pharyngeal epithelium, which indicate that PO could serve as a protecting agent against environmental pathogens in D. japonica.
authors.affiliation: School of Life Sciences, Shandong University of Technology, Zibo 255049, China. pangqiuxiang@163.com
authors.forename: Qiuxiang
authors.initials: Q
authors.lastname: Pang
authors.forename: Xuemei
authors.initials: X
authors.lastname: Liu
authors.forename: Bosheng
authors.initials: B
authors.lastname: Zhao
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Jiang
authors.forename: Feng
authors.initials: F
authors.lastname: Su
authors.forename: Xiufang
authors.initials: X
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Nie
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Sun
mesh_terms: D000818:Animals; D004586:Electrophoresis; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010670:Phenylthiourea / Q000494:pharmacology; D010932:Planarians / Q000201:enzymology*; D021381:Protein Transport; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D010670:Phenylthiourea; D014442:Monophenol Monooxygenase