title: Melanosis in Penaeus monodon: Involvement of the Laccase-like Activity of Hemocyanin.
abstract: In shrimp, the development of postmortem melanosis resulting from phenoloxidase activities leads to important economic losses. Phenoloxidase enzymes include catechol oxidases, laccases, and tyrosinases, but hemocyanin is also capable of phenoloxidase activities. These activities have been explored in Penaeus monodon, using different substrates. Results highlighted that tyrosinase-specific substrates were little oxidized, whereas hydroquinone (laccase-specific substrate) was more highly oxidized than l-DOPA (nonspecific substrate) in the pereopods and pleopods. Global phenoloxidase activity, assayed with l-DOPA, did not appear thermally stable over time and probably resulted from phenoloxidase enzymes. Conversely, the laccase-like activity assayed with hydroquinone was thermally stable over time, reflecting the thermal stability of hemocyanin. Independently of the anatomical compartment, the temperature, or the substrate, the highest activities were assayed in the cuticular compartments. This study demonstrates the complexity of phenoloxidase activities in P. monodon, and the importance of considering all the activities, including laccase-like activities such as that of hemocyanin.
authors.affiliation: Université Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette , F-62200 Boulogne sur Mer, France.|Université Lille , F-59000 Lille, France.|Université Artois , F-62000 Arras, France.|INRA , France.|ISA , F-59000 Lille, France.
authors.forename: Cédric Le
authors.initials: CL
authors.lastname: Bris
authors.affiliation: Université Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette , F-62200 Boulogne sur Mer, France.|Université Lille , F-59000 Lille, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Cudennec
authors.affiliation: Université Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette , F-62200 Boulogne sur Mer, France.|Université Lille , F-59000 Lille, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Dhulster
authors.affiliation: Université Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette , F-62200 Boulogne sur Mer, France.|Université Lille , F-59000 Lille, France.
authors.forename: Djamel
authors.initials: D
authors.lastname: Drider
authors.affiliation: ANSES, Laboratoire de Sécurité des Aliments-Département des Produits de la Pêche et de l'Aquaculture , Boulevard du Bassin Napoléon, F-62200 Boulogne sur Mer, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Duflos
authors.affiliation: Université Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette , F-62200 Boulogne sur Mer, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Grard
mesh_terms: D000818:Animals; D004795:Enzyme Stability; D006433:Hemocyanins / Q000737:chemistry / Q000378:metabolism*; D042845:Laccase / Q000737:chemistry / Q000378:metabolism*; D008543:Melanins / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D033561:Penaeidae / Q000201:enzymology* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D008543:Melanins; D006433:Hemocyanins; D042845:Laccase
keywords: Penaeus monodon; hemocyanin; laccase; melanosis; phenoloxidase activities