1.11.1.11 additional information - additional information - 439855 1.11.1.11 additional information - additional information ascorbate can saturate the ascorbate-dependent hemoperoxidase activity indicating that the enzyme obeys Michaelis-Menten kinetics 439880 1.11.1.11 additional information - additional information both forms of the enzyme show a very high affinity for H2O2, Km values below 0.005 439856 1.11.1.11 additional information - additional information kinetics, overview 764715 1.11.1.11 additional information - additional information Km of recombinant enzyme-B produced in E. coli 439881 1.11.1.11 additional information - additional information Km values comparable with those of higher plants 439876 1.11.1.11 additional information - additional information pre-steady state and steady-state kinetic analysis of wild-type and mutant enzymes, formation of high-valent Compound I and Compound II intermediates, detailed overview. The steady-state oxidation of ascorbate by APX does not obey simple Michaelis-Menten kinetics, and a sigmoidal dependence of rate on substrate concentration is observed. The mutant A134P variant behaves similarly. In contrast, oxidation of guaiacol by A134P exhibits conventional Michaelis-Menten type kinetics 765196 1.11.1.11 additional information - additional information steady-state Michaelis-Menten kietics 764871 1.11.1.11 additional information - additional information the reaction does not follow Michaelis-Menten kinetics, Hill plots 439855 1.11.1.11 additional information - additional information untreated cells, sigmoidal dependence of reaction rate on ascorbate concentration, in heat shock cells, hyperbolic dependence of reaction rate on ascorbate concentration and 5-fold decrease in Km-value 657063 1.11.1.11 0.000043 - 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) pH 7.0, temperature not specified in the publication. Hill coefficient n is 1.0 726123 1.11.1.11 0.011 - H2O2 recombinant enzyme 1 439869 1.11.1.11 0.017 - guaiacol 25°C, mutant enzyme W208F 685400 1.11.1.11 0.02 - H2O2 - 439871 1.11.1.11 0.02 - H2O2 recombinant enzyme 439864 1.11.1.11 0.0217 - H2O2 wild-type enzyme 686657 1.11.1.11 0.022 - H2O2 wild-type enzyme 684930, 686710 1.11.1.11 0.024 - H2O2 - 439865 1.11.1.11 0.024 - H2O2 recombinant enzyme 2 439869 1.11.1.11 0.025 - cytochrome c 25°C, mutant enzyme W208F 685400 1.11.1.11 0.0287 - H2O2 in 50 mM potassium phosphate (pH 7.0), at 22°C 713299 1.11.1.11 0.029 - cytochrome c pH 7.4, 25°C 743696 1.11.1.11 0.033 - H2O2 pH 6.5, APX 1 657113 1.11.1.11 0.0343 - H2O2 mutant enzyme C126A 684930 1.11.1.11 0.035 - H2O2 - 439861 1.11.1.11 0.038 - H2O2 pH 6.4, untreated cells 657063 1.11.1.11 0.041 - L-ascorbate pH 6.4, heat-shock cells 657063 1.11.1.11 0.042 - H2O2 wild-type enzyme 686710 1.11.1.11 0.047 - H2O2 pH 6.4, heat-shock cells 657063 1.11.1.11 0.05 - H2O2 mutant enzyme C25S 686710 1.11.1.11 0.05 - H2O2 native and recombinant enzyme 439874 1.11.1.11 0.05 - H2O2 pH 8.0 654139 1.11.1.11 0.052 - H2O2 mutant enzyme C25S/C121S 686710 1.11.1.11 0.0537 - H2O2 mutant enzyme C26S/C126A 684930 1.11.1.11 0.056 - H2O2 substrate: L-ascorbic acid 439858 1.11.1.11 0.06 - H2O2 pH 7.5, 25°C 654378 1.11.1.11 0.0606 - H2O2 mutant enzyme C26S 684930 1.11.1.11 0.061 - H2O2 mutant enzyme C26S 686710 1.11.1.11 0.065 - H2O2 pH 6.2, 30°C, cell-free enzyme extract 764715 1.11.1.11 0.07 - ascorbate recombinant PgAPX 699802 1.11.1.11 0.076 - ascorbate - 439875 1.11.1.11 0.076 - H2O2 pH 7.0, APX 2 657113 1.11.1.11 0.08 - H2O2 - 439875 1.11.1.11 0.0939 - H2O2 mutant enzyme W35F 684930, 686657 1.11.1.11 0.102 - L-ascorbate mutant S160M, pH 7.0, 25°C 655789 1.11.1.11 0.11 - H2O2 pH 7.4, 37°C 724680 1.11.1.11 0.111 - ascorbate - 439871 1.11.1.11 0.117 - L-ascorbate wild-type enzyme 686710 1.11.1.11 0.12 - H2O2 - 439867, 689240 1.11.1.11 0.12 - H2O2 25°C 688913 1.11.1.11 0.123 - L-ascorbate in 50 mM potassium phosphate (pH 7.0), at 22°C 713299 1.11.1.11 0.13 - H2O2 - 439868 1.11.1.11 0.13 - L-ascorbate pH 7.0, 25°C 764871 1.11.1.11 0.136 - H2O2 mutant enzyme C26S/W35F/C126A 684930 1.11.1.11 0.14 - ascorbate - 439867 1.11.1.11 0.15 - L-ascorbate pH 8.0 654139 1.11.1.11 0.167 - L-ascorbate mutant enzyme W35F 684930 1.11.1.11 0.17 - L-ascorbate mutant enzyme W35F 686657 1.11.1.11 0.17 - L-ascorbate pH 7.0, 25°C, mutant H42E 655435 1.11.1.11 0.19 - L-ascorbate mutant enzyme C26S/W35F/C126A 684930 1.11.1.11 0.19 - L-ascorbate pH 7.4, 25°C 743696 1.11.1.11 0.198 - L-ascorbate mutant enzyme C126A 684930 1.11.1.11 0.2 - ascorbate pH 7.0, APX 2 657113 1.11.1.11 0.22 - H2O2 substrate: pyrogallol 439858 1.11.1.11 0.229 - L-ascorbate pH 6.4, untreated cells 657063 1.11.1.11 0.23 - H2O2 pH 7.0, 25°C 764871 1.11.1.11 0.285 - L-ascorbate pH 6.2, 30°C, cell-free enzyme extract 764715 1.11.1.11 0.3 - ascorbate pH 7.5, 25°C 654378 1.11.1.11 0.333 - ascorbate recombinant enzyme 1 439869 1.11.1.11 0.34 - ascorbate native and recombinant enzyme 439874 1.11.1.11 0.35 - ascorbate recombinant enzyme 439864 1.11.1.11 0.355 - L-ascorbate wild-type, pH 7.0, 25°C 655789 1.11.1.11 0.38 - ascorbate - 439861 1.11.1.11 0.394 - L-ascorbate mutant enzyme C25S/C121S 686710 1.11.1.11 0.395 - L-ascorbate wild-type enzyme 684930, 686657, 686710 1.11.1.11 0.4 - L-ascorbate pH 6.5, APX 1 657113 1.11.1.11 0.4 - L-ascorbate pH 7.4, 37°C 724680 1.11.1.11 0.402 - ascorbate - 439865 1.11.1.11 0.41 - L-ascorbate pH 7.0, 25°C, wild-type 655435 1.11.1.11 0.41 - L-ascorbic acid - 439858 1.11.1.11 0.43 - L-ascorbate - 689240 1.11.1.11 0.467 - ascorbate recombinant enzyme 2 439869 1.11.1.11 0.493 - L-ascorbate recombinant full length enzyme, in 50 mM potassium phosphate buffer, pH 7.0, at 22°C 711139 1.11.1.11 0.496 - L-ascorbate mutant enzyme C25S 686710 1.11.1.11 0.5 - L-ascorbate pH 7.0, temperature not specified in the publication 743788 1.11.1.11 0.506 - L-ascorbate mutant enzyme C26S/C126A 684930 1.11.1.11 0.53 - L-ascorbate 25°C 688913 1.11.1.11 0.566 - L-ascorbate mutant enzyme C26S 684930, 686710 1.11.1.11 0.77 - ascorbate - 439868 1.11.1.11 0.804 - L-ascorbate pH 7.0, temperature not specified in the publication. Non-Michaelis-Menten kinetics, Hill ccoefficient n is 1.6 726123 1.11.1.11 1.8 - guaiacol recombinant enzyme 439864 1.11.1.11 2.4 - pyrogallol recombinant enzyme 439864 1.11.1.11 2.9 - ascorbate enzyme form C 439856 1.11.1.11 2.9 - guaiacol pH 7.0, 25°C, mutant H42E 655435 1.11.1.11 3.43 - H2O2 pH 7.0, temperature not specified in the publication 743788 1.11.1.11 4.2 - guaiacol will-type enzyme 439873 1.11.1.11 6 - cytochrome c 25°C, wild-type enzyme 685400 1.11.1.11 6.1 - guaiacol Cys32Ser mutant 439873 1.11.1.11 6.5 - ascorbate enzyme form B 439856 1.11.1.11 6.7 - guaiacol 25°C, wild-type enzyme 685400 1.11.1.11 7.4 - guaiacol enzyme form C 439856 1.11.1.11 9.6 - pyrogallol - 439858 1.11.1.11 9.7 - guaiacol DTNB-modified enzyme 439873 1.11.1.11 12.3 - guaiacol pH 7.0, 25°C, wild-type 655435