title: Phenoloxidases in ascidian hemocytes: characterization of the pro-phenoloxidase activating system.
abstract: The phenoloxidase (PO) activity of the hemocytes lysate supernatant from three ascidians species, assayed by means of 3-methyl-2-benzothiazolinone hydrazone hydrochloride, have been compared. PO-containing hemocytes were identified by a cytochemical reaction and the enzymatic activity measured by a spectrophotometric assay of lysate supernatant from hemocyte populations separated on a discontinuous Percoll density gradient. In Styela plicata, the enzyme appeared to be contained in morula cells only. In Ciona intestinalis, PO activity was shown in univacuolar refractile granulocyte and granular hemocyte. In Phallusia mammillata both compartment cell and granular hemocytes were positive. Enzymatic assay following electrophoretic analysis on polyacrylamide gel electrophoresis (PAGE) or SDS-PAGE indicated that hemocyte lysate presented orthodiphenoloxidase (catecholase) activity. The enzymes from the three species differed in molecular size, activating substances and trypsin sensitivity.
authors.affiliation: Laboratory of Marine Immunobiology, Department of Animal Biology, University of Palermo, Via Archirafi, 18, 90123 Palermo, Italy. nicpar@unipa.it
authors.forename: Nicolò
authors.initials: N
authors.lastname: Parrinello
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Arizza
authors.forename: Cinzia
authors.initials: C
authors.lastname: Chinnici
authors.forename: Daniela
authors.initials: D
authors.lastname: Parrinello
authors.forename: Matteo
authors.initials: M
authors.lastname: Cammarata
mesh_terms: D000818:Animals; D052160:Benzothiazoles; D004789:Enzyme Activation; D006434:Hemocytes / Q000166:cytology / Q000201:enzymology*; D006835:Hydrazones; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000378:metabolism*; D013844:Thiazoles / Q000378:metabolism; D014561:Urochordata / Q000166:cytology / Q000201:enzymology*
chemical_list: D052160:Benzothiazoles; D006835:Hydrazones; D013844:Thiazoles; D014442:Monophenol Monooxygenase; C002536:3-methyl-2-benzothiazolone hydrazone