title: Activation of phenoloxidase activity by humoral lectin in hemocytes of freshwater crab Paratelphusa jacquemontii.
abstract: The lectin, Pjlec isolated from the hemolymph of the freshwater crab Paratelphusa jacquemontii hemagglutinated (HA) with mice, rabbit and rat erythrocytes. However, the lectin failed to agglutinate neraminidase treated asialylated erythrocytes showing its sialic acid specificity. The poyacyrlamide gel electrophoresis of lectin yielded 310kDa proteins, on sodium sulphate dodecyl (SDS) gel appeared as a tetramer with subunits of 76kDa. The observation of in vitro phagocytosis in granular hemocytes of lectin opsonized rabbit erythrocyte by Transmission electron microscopy (TEM) showed the release of lytic vesicles by exocytosis prior to engulfment. The Pjlec lectin also showed an ability to oxidize L-3, 4 dihydroxyphenylalanine (L-DOPA) and in hemocyte lysate preparation (HLS) was enhanced on reduction with SDS and on proteolytic cleavage with trypsin. The lectin appeared to have a regulatory role in activation of enzyme activity associated with phagocytosis and melanin formation.
authors.affiliation: Laboratory of Pathobiology, Department of Zoology, University of Madras, Chennai, Tamil Nadu 600025, India. Electronic address: maghilthilak@yahoo.com.
authors.forename: Maghil
authors.initials: M
authors.lastname: Denis
authors.affiliation: Laboratory of Pathobiology, Department of Zoology, University of Madras, Chennai, Tamil Nadu 600025, India.
authors.forename: Sivakumar Mullaivanam
authors.initials: SM
authors.lastname: Ramasamy
authors.affiliation: Laboratory of Pathobiology, Department of Zoology, University of Madras, Chennai, Tamil Nadu 600025, India.
authors.forename: Tamilarasan
authors.initials: T
authors.lastname: Kamalanathan
authors.affiliation: Laboratory of Pathobiology, Department of Zoology, University of Madras, Chennai, Tamil Nadu 600025, India.
authors.forename: Karthigayani
authors.initials: K
authors.lastname: Thayappan
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Chennai, Tamil Nadu 600025, India.
authors.forename: Prabu
authors.initials: P
authors.lastname: Mannarreddy
authors.affiliation: Laboratory of Pathobiology, Department of Zoology, University of Madras, Chennai, Tamil Nadu 600025, India.
authors.forename: Bhuvaneswari Selvaputhiran
authors.initials: BS
authors.lastname: Doss
authors.affiliation: Laboratory of Pathobiology, Department of Zoology, University of Madras, Chennai, Tamil Nadu 600025, India.
authors.forename: Arumugam
authors.initials: A
authors.lastname: Munusamy
mesh_terms: D000818:Animals; D003386:Brachyura / Q000276:immunology*; D004789:Enzyme Activation / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D006386:Hemagglutination Tests; D006434:Hemocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D006458:Hemolymph / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D056724:Immunity, Humoral; D037102:Lectins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects; D019800:Phenol / Q000378:metabolism; D011817:Rabbits; D051381:Rats
chemical_list: D037102:Lectins; D019800:Phenol; D014442:Monophenol Monooxygenase
keywords: Hemagglutination; Lectin; Paratelphusa jacquemontii; Phagocytosis; Phenoloxidase