title: In vitro antibacterial analysis of phenoloxidase reaction products from the sea cucumber Apostichopus japonicus.
abstract: Three phenoloxidases (POs) of Apostichopus japonicus, AjPOs (AjPO1, AjPO2 and AjPO3), were partially purified from the coelomocytes with an electrophoretic method, and then employed for the in vitro antibacterial analysis. Using L-3,4-dihydroxyphenylalanine (L-DOPA) as a substrate, AjPO1 and AjPO2-derived compounds inhibited the growth of Vibrio splendidus and Staphylococcus aureus, while AjPO3-derived compounds only inhibited the growth of V. splendidus. When dopamine was used as a substrate, AjPO1 and AjPO3-derived compounds inhibited the growth of V. splendidus and Vibrio harveyi, while AjPO2-derived compounds only inhibited the growth of V. splendidus. Moreover, AjPO1-derived compounds showed stronger inhibition in V. harveyi than AjPO3-derived compounds did. However, all of the three AjPO reaction products showed no inhibitions on the growth of Pseudoalteromonas nigrifaciens, Shewanella baltica, Micrococcus lysodeikticus, Streptococcus dysgalactiae and Nocardiopsis sp. with L-DOPA or dopamine as a substrate. Scanning electron microscope (SEM) observation of V. harveyi treated by AjPOs and dopamine showed that AjPO1-derived compounds resulted in massive bacteriolysis, AjPO2-derived compounds caused no obvious alteration on bacterial morphology, and AjPO3-derived compounds increased the ratio of spheroidal bacteria. All these results suggested that AjPO reaction products derived by L-DOPA and dopamine had different but limited antibacterial spectrum, and the different antibacterial effects observed among three AjPOs resulted from the different reaction products generated by AjPOs with the same substrate.
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China. Electronic address: zunchunz@hotmail.com.
authors.forename: Zunchun
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Cong
authors.initials: C
authors.lastname: Cong
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Guan
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Bai
authors.initials: B
authors.lastname: Wang
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Bei
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Aifu
authors.initials: A
authors.lastname: Yang
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning 116023, PR China.
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Sun
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D001433:Bacteriolysis / Q000187:drug effects*; D066298:In Vitro Techniques; D007980:Levodopa / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D014442:Monophenol Monooxygenase / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D012616:Sea Cucumbers / Q000201:enzymology* / Q000276:immunology*; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D014733:Vibrio / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D000900:Anti-Bacterial Agents; D007980:Levodopa; D014442:Monophenol Monooxygenase
keywords: Antibacterial effects; Dopamine; L-3,4-dihydroxyphenylalanine; Phenoloxidases; Sea cucumber (Apostichopus japonicus)