title: Enzyme characterisation and gene expression profiling of Atlantic salmon chicken- and goose-type lysozymes.
abstract: Lysozymes represent important innate immune components against bacteria. In this study, Atlantic salmon (Salmo salar) goose (g-) and chicken (c-) types of lysozyme were subjected to protein characterisations and tissue expression analyses. Specific bacterial protein inhibitors of g- and c-type lysozymes were employed to discriminate between respective enzyme activities. Blood, gills and liver contained activities exclusive for the g-type lysozyme. Only haematopoietic organs (head kidney and spleen) contained enzyme activities of both g- and c-lysozyme enzymes and c-type activity was not found outside these organs. Gene transcript levels proportional to enzyme activity levels were detected for the g-type lysozyme but not for the c-type. In vitro studies revealed significant induction of c-type gene expression and enzyme activity in macrophages after incubation with lipopolysaccharide (LPS) while expression of the g-type lysozyme gene was unaffected. The activity of purified native c-type enzyme was profoundly reduced by divalent cations and displayed low tolerance to monovalent cations, while the native g-type lysozyme was stimulated by monovalent cations and tolerated low concentrations of divalent cations. Activities of both enzymes increased with temperature elevations up to 60°C. The native g-type lysozyme responses to temperature in particular are in apparent conflict to the ones for the recombinant salmon g-lysozyme. Our results imply separate expression regulations and different functions of c- and g-type lysozymes in salmon. LPS-induced expression of c-type lysozyme and broad constitutive tissue distribution of g-type lysozyme in salmon is different from findings in other studied fish species.
authors: Marine Biotechnology, Nofima, Muninbakken 9-13, 9291 Tromsø, Norway.
authors: Bjørnar
authors: B
authors: Myrnes
authors: Marit
authors: M
authors: Seppola
authors: Audny
authors: A
authors: Johansen
authors: Kersti
authors: K
authors: Overbø
authors: Lien
authors: L
authors: Callewaert
authors: Lise
authors: L
authors: Vanderkelen
authors: Chris W
authors: CW
authors: Michiels
authors: Inge W
authors: IW
authors: Nilsen
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000378:metabolism; D002413:Cations, Divalent / Q000378:metabolism; D002414:Cations, Monovalent / Q000378:metabolism; D002478:Cells, Cultured; D004789:Enzyme Activation; D029941:Fish Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005880:Gills / Q000378:metabolism; D060226:Head Kidney / Q000378:metabolism; D006358:Hot Temperature; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000276:immunology; D008099:Liver / Q000378:metabolism; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D009113:Muramidase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009928:Organ Specificity; D020317:Salmo salar / Q000235:genetics / Q000276:immunology*; D013154:Spleen / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D002414:Cations, Monovalent; D029941:Fish Proteins; D008070:Lipopolysaccharides; D009113:Muramidase