Interaction of Ceruloplasmin and 5-Lipoxygenase

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A. V. Sokolov^1*, E. A. Golenkina², V. A. Kostevich¹, V. B. Vasilyev¹, and G. F. Sud’ina²

¹Research Institute of Experimental Medicine, ul. Pavlova 12, 197376 St. Petersburg, Russia; fax: (812) 234-9489; E-mail: biochemsokolov@gmail.com

²Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; fax: (495) 939-3181

^* To whom correspondence should be addressed.

Received July 26, 2010; Revision received September 17, 2010

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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.

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KEY WORDS: protein–protein interaction, inflammation, leukotrienes, 5-lipoxygenase, ceruloplasmin

DOI: 10.1134/S0006297910120072

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