title: Activation of peroxidase-catalyzed oxidation of aromatic amines with 2-aminothiazole and melamine.
abstract: The peroxidase-catalyzed oxidation of 3,3;,5,5;-tetramethylbenzidine (TMB), ortho-phenylenediamine (PDA), and 5-aminosalicylic acid (5-ASA) is significantly accelerated in the presence of 2-aminothiazole (AT) and melamine (MA), and an increase in their concentrations is associated with a parallel increase in the k(cat) and K(m) values for TMB and PDA. The activation of the peroxidase-catalyzed oxidation of TMB and PDA is quantitatively characterized by a coefficient (degree) alpha (M(-1)) which significantly depends on pH in the range 6.2-6.4, 6.4-7.4, and 6.0-7.4 for the TMB-AT, TMB-MA, and PDA-MA pairs, respectively. An increase in the coefficient alpha with increase in pH confirms nucleophilicity of activation of the peroxidase-catalyzed oxidation of the aromatic amines in the presence of AT and MA. Under optimal conditions the coefficients alpha for the TMB-AT, PDA-AT, TMB-MA, and PDA-MA pairs vary in the limits of (1.90-3.53)*10(3) M(-1).
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, 220141, Belarus.
authors.forename: E I
authors.initials: EI
authors.lastname: Karasyova
authors.forename: I V
authors.initials: IV
authors.lastname: Naumchik
authors.forename: D I
authors.initials: DI
authors.lastname: Metelitza
mesh_terms: D000588:Amines / Q000378:metabolism*; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000378:metabolism*; D014227:Triazines / Q000378:metabolism*
chemical_list: D000588:Amines; D013844:Thiazoles; D014227:Triazines; C004483:2-aminothiazole; D009195:Peroxidase; C011907:melamine