title: Hemocyanin in the exoskeleton of crustaceans: enzymatic properties and immunolocalization.
abstract: We investigated the enzymatic properties and immunohistochemical localization of cuticular hemocyanin, a known oxygen transporter in the prawn Penaeus japonicus. The molecular weight of hemocyanin purified from the cuticle was estimated to be 67-77 k using SDS-PAGE, and the purified protein was effectively converted into a phenoloxidase-like enzyme by an SDS-treatment. The activated enzyme catalyzed the o-hydroxylation of monophenols and the oxidation of o-diphenols and was inhibited by typical inhibitors of phenoloxidase. These characteristics were nearly identical to the enzymatic properties of hemolymph hemocyanin. Immunological detection showed a diffuse distribution of hemocyanin over the exocuticle and endocuticle, and a higher signal level was observed in the latter. Based on these results, roles of hemocyanin in various physiological processes such as immune response and sclerotization of the cuticle were discussed.
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Adachi
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Endo
authors.forename: Toshiki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Takaaki
authors.initials: T
authors.lastname: Nishioka
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirata
mesh_terms: D000818:Animals; D004789:Enzyme Activation; D006433:Hemocyanins / Q000302:isolation & purification / Q000378:metabolism*; D006458:Hemolymph / Q000201:enzymology; D007150:Immunohistochemistry; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D033561:Penaeidae / Q000033:anatomy & histology / Q000201:enzymology*; D010636:Phenols / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
chemical_list: D010636:Phenols; D012967:Sodium Dodecyl Sulfate; D006433:Hemocyanins; D014442:Monophenol Monooxygenase