title: [New approaches to the measurement of the concentration and peroxidase activity of myeloperoxidase in human blood plasma].
abstract: A novel method for spectrometrical measurement of myeloperoxidase (MPO) activity in plasma with o-dianisidine (DA) as a substrate is proposed. We have determined the optimal conditions, including the pH and hydrogen peroxide concentration, under which MPO is the main contributor to DA oxidation in plasma. Specific MPO inhibitors, salicylhydroxamic acid or (4-aminobenzoyl)hydrazide, are added to measure the activity of other heme-containing peroxidases (mainly hemoglobin and its derivatives) and subtract their contribution from the total plasma peroxidase activity. Plasma MPO concentrations are quantified by a new enzyme-linked immunosorbent assay (ELISA) developed by us and based on the use of antibodies raised in rats and rabbits. The sensitivity of this ELISA is high: 0.2-250 ng/ml. A direct and significant (P < 0.0001) correlation was observed between the MPO activities measured spectrometrically and by ELISA in blood samples from 38 healthy donors. The proposed approaches to MPO measurement in plasma can be used to evaluate the enzyme activity and concentration, as well as the efficacy of mechanisms by which MPO is regulated under physiological conditions and against the background of various inflammatory diseases.
authors.affiliation: Department of Biophysics, Belarusian State University, Minsk, Belarus. irinagorudko@rambler.ru
authors.forename: I V
authors.initials: IV
authors.lastname: Gorudko
authors.forename: O S
authors.initials: OS
authors.lastname: Cherkalina
authors.forename: A V
authors.initials: AV
authors.lastname: Sokolov
authors.forename: M O
authors.initials: MO
authors.lastname: Pulina
authors.forename: E T
authors.initials: ET
authors.lastname: Zakharova
authors.forename: V B
authors.initials: VB
authors.lastname: Vasil'ev
authors.forename: S N
authors.initials: SN
authors.lastname: Cherenkevich
authors.forename: O M
authors.initials: OM
authors.lastname: Panasenko
mesh_terms: D000818:Animals; D003962:Dianisidine / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007249:Inflammation / Q000097:blood / Q000201:enzymology; D009195:Peroxidase / Q000097:blood*; D011817:Rabbits; D051381:Rats; D012680:Sensitivity and Specificity
chemical_list: D004791:Enzyme Inhibitors; D006861:Hydrogen Peroxide; D009195:Peroxidase; D003962:Dianisidine