Hemocyanin in the exoskeleton of crustaceans: enzymatic properties and immunolocalization.
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.
Adachi
Kohsuke
K
Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Endo
Hirotoshi
H
Watanabe
Toshiki
T
Nishioka
Takaaki
T
Hirata
Takashi
T
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
D010636:Phenols; D012967:Sodium Dodecyl Sulfate; D006433:Hemocyanins; D014442:Monophenol Monooxygenase