Isolation and Characterization of Myeloperoxidase from Leukocytes of Rat Peritoneal Fluid

V. I. Morozov,^1,2 P. V. Tsyplenkov,¹ V. N. Kokryakov,³ K. N. Volkov,¹ and N. A. Vinogradova⁴

¹Department of Biochemistry, Institute of Physical Culture, pr. Dinamo 2, St. Petersburg, 197042 Russia; fax: (7-812) 235-01-31.

²To whom correspondence should be addressed.

³Department of General Pathology and Pathophysiology, Institute of Experimental Medicine, Russian Academy of Medical Sciences, ul. Akademika Pavlova 12, St. Petersburg, 197376 Russia; fax: (7-812) 234-94-93.

⁴Laboratory of Physiology of Cell Cycle, Institute of Cytology, Russian Academy of Sciences, Tikhoretskii pr. 4, St. Petersburg, 194064 Russia; fax: (7-812) 247-03-41.

Submitted September 12, 1996; revision submitted February 7, 1997.

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Myeloperoxidase (MPO) was isolated from rat peritoneal leukocytes with a yield of 51% and A₄₃₀/A₂₈₀ = 0.75-0.80, and its physicochemical properties were studied. The molecular weight of the MPO is about 150 kD. The MPO was assayed for amino acid content. We used substrate mixture containing phenol, 4-aminoantipyrine, and H₂O₂ to detect 10^-10 M of the enzyme. The MPO was localized in rat blood neutrophils using polyclonal anti-MPO antibodies and secondary fluorescein isothiocyanate-labeled antibodies. Immunofluorimetric assay (IFMA) was developed for quantitative measurement of the MPO. The MPO and leukocytes can iodinate BSA using NaI or thyroxine as the source of iodine.

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KEY WORDS: leukocytes, neutrophils, myeloperoxidase, iodination.

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