Two types of phenoloxidases contribute to hemolymph PO activity in spiny Lobster.
Food Chem
; 260: 166-173, 2018 Sep 15.
Article
in En
| MEDLINE
| ID: mdl-29699658
ABSTRACT
Phenoloxidases (POs) play a crucial role in melanization of crustaceans. There are at least two types of POs characterized in crustaceans the conventional type (POα here) that is expressed in hemocytes and POß, a secreted protein synthesized in the hepatopancreas. We investigated the source of PO activity in the hemolymph of a lobster and determined the kinetic parameters of mono- and di-PO activities. In the lobster hemolymph, POα, which formed a hexamer similar to both POß and hemocyanin, contributed to PO activity, whereas the amount of POß was low. Kinetic analyses using purified prophenoloxidase of crustaceans showed that lobster POα has a higher rate constant, while shrimp POß has higher specificity in both mono- and di-PO reactions, when tyramine and dopamine were employed as substrates. There should be at least two types of PO molecules in crustacean hemolymph, but the dominant PO molecule type varies among species.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Hemolymph
/
Monophenol Monooxygenase
/
Palinuridae
Limits:
Animals
Language:
En
Journal:
Food Chem
Year:
2018
Document type:
Article