Activated phenoloxidase from Tenebrio molitor larvae enhances the synthesis of melanin by using a vitellogenin‐like protein in the presence of dopamine

• DOI: 10.1046/j.1432-1327.2000.01402.x
• Publication Date: 2003-03-11T17:47:16Z
• Authors: Kwang Moon Lee; Kum Young Lee; Hye Won Choi; Mi Young Cho; Tae Hyuk Kwon; Shun‐ichiro Kawabata; Bok Luel Lee
• Keywords: Prophenoloxidase; Hemolymph; Vitellogenin; Sephadex; Catechol oxidase

One of the biological functions activated phenoloxidase in arthropods is synthesis melanin around invaded foreign materials. However, little known about how synthesizes at molecular level. Even though it has been suggested that quinone derivatives generated by might use endogenous protein components for arthropods, there no report engaged induced phenoloxidase. In this study, to isolate and characterize proteins involved synthesis, we prepared vitro prophenoloxidase activating solution (designated G‐100 solution), specifically showing activity presence Ca 2+ β‐1,3‐glucan, from hemolymph larvae coleopteran Tenebrio molitor using a Sephadex column. When was incubated with dopamine induce four types (160 kDa, prophenoloxidase, 45 kDa) disappeared SDS/PAGE under reducing conditions. Under identical conditions, but including phenylthiourea as inhibitor added solution, three these did not disappear. To melanization‐engaging proteins, first purified 160‐kDa homogeneity raised polyclonal antibody against it. Analysis cDNA revealed consisted 1439 amino‐acid residues showed partial homology Caenorhabditis elegans vitellogenin precursor‐6 (19.7%). Western blot analysis when active synthesis. Furthermore, deficient it, enhanced compared same without protein. These data support conclusion vitellogenin‐like arthropod