title: Interaction of ceruloplasmin and 5-lipoxygenase.
abstract: The interaction between ceruloplasmin (CP), the multicopper oxidase of human plasma, and 5-lipoxygenase (5-LO), the key enzyme of leukotriene synthesis, is shown for the first time. By Western-blotting and mass spectrometry of tryptic fragments, it is shown that 5-LO from protein extract of human leukocytes binds with immobilized CP. Dose-dependent influence of intact CP on leukotrienes synthesis is found: CP reduced leukotrienes synthesis in leukocytes in a dose above 50 µg/ml (normal CP concentration in plasma is about 300-400 µg/ml). Proteolyzed CP and apo-form of CP is unable to inhibit activity of 5-LO. CP increased activity of 5-LO at low doses (5-10 µg/ml). On the whole, the influence of CP on phagocytosis index of leukocytes coordinates with influence on activity of 5-LO: the index increased in the range of 2-10 µg/ml CP and decreased at doses of CP above 40 µg/ml. The dual role of CP in regulation of cellular response of leukocytes is discussed.
authors.affiliation: Research Institute of Experimental Medicine, St. Petersburg 197376, Russia. biochemsokolov@gmail.com
authors.forename: A V
authors.initials: AV
authors.lastname: Sokolov
authors.forename: E A
authors.initials: EA
authors.lastname: Golenkina
authors.forename: V A
authors.initials: VA
authors.lastname: Kostevich
authors.forename: V B
authors.initials: VB
authors.lastname: Vasilyev
authors.forename: G F
authors.initials: GF
authors.lastname: Sud'ina
mesh_terms: D000595:Amino Acid Sequence; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism*; D002570:Ceruloplasmin / Q000378:metabolism*; D057075:Enzyme Assays; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism; D010587:Phagocytosis; D013481:Superoxides / Q000378:metabolism; D015054:Zymosan / Q000378:metabolism
chemical_list: D013481:Superoxides; D015054:Zymosan; D001094:Arachidonate 5-Lipoxygenase; D002570:Ceruloplasmin