1.11.1.11 2,2,6,6-tetramethylpiperidinyl-1-oxide formation of 2,2,6,6-tetramethylpiperidinyl-1-oxy-adducts and subsequent oxidation of the cysteine residue located near the propionate group of heme leads to loss of enzyme activity 143351 1.11.1.11 2,2,6,6-tetramethylpiperidinyl-1-oxyl radical formation of 2,2,6,6-tetramethylpiperidinyl-1-oxy-adducts and subsequent oxidation of the cysteine residue located near the propionate group of heme leads to loss of enzyme activity 143350 1.11.1.11 2,6-dichloroisonicotinic acid 54% inhibition at 0.1 mM, 95% inhibition at 1 mM, the inhibition is not time-dependent 108006 1.11.1.11 2,6-dihydroxybenzoic acid biologically active, 72% inhibition at 0.2 mM 31294 1.11.1.11 2-mercaptoethanol enzyme form C: 50% inhibition at 5 mM, 6 min, 100% inhibition after 18 min 63 1.11.1.11 2-mercaptoethanol not inhibitory at 0.5 mM, 31% inhibition at 5 mM 63 1.11.1.11 2-mercaptoethanol 70.3% activity remaining at 1 mM 63 1.11.1.11 2-nitrobenzoic acid 1.48% activity remaining at 1 mM 48532 1.11.1.11 3,3'-dithiobis(6-nitrobenzoic acid) 5 mM, 80% residual activity, APX 1, 24% residual activity, APX 2 55863 1.11.1.11 3,5-dichlorosalicylic acid biologically active, 59% inhibition at 0.2 mM 3266 1.11.1.11 3-Hydroxybenzoic acid biologically inactive, 28% inhibition at 0.2 mM 3970 1.11.1.11 4-aminosalicylic acid biologically inactive, 9% inhibition at 0.2 mM 5110 1.11.1.11 4-chlorosalicylic acid biologically active, 58% inhibition at 0.2 mM 49808 1.11.1.11 5,5'-dithiobis(2-nitrobenzoic acid) 40% inhibition at 0.1 mM 221 1.11.1.11 5,5'-dithiobis(2-nitrobenzoic acid) 96% inhibition at 0.5 mM 221 1.11.1.11 5-chlorosalicylic acid biologically active, 73% inhibition at 0.2 mM 11183 1.11.1.11 Al3+ - 264 1.11.1.11 Al3+ inhibition in the range of 0.01-0.5 mM 264 1.11.1.11 Al3+ inhibits the enzyme at 1-5 mM, almost complete inhibition at 10 mM 264 1.11.1.11 azide - 230 1.11.1.11 azide 46% inhibition at 0.5 mM 230 1.11.1.11 beta-mercaptoethanol 29% inhibition at 3 mM 773 1.11.1.11 Br- marked inhibition at 1 mM 332 1.11.1.11 C2H2 potent inhibitor 4794 1.11.1.11 C2H2 recombinant enzyme 1: 94% inhibition at 0.1 ml per l, recombinant enzyme 2: 2% inhibition at 0.1 ml per l 4794 1.11.1.11 Ca2+ - 15 1.11.1.11 Ca2+ inhibits the enzyme at 1-10 mM 15 1.11.1.11 Cd2+ inhibits the enzyme at 1-10 mM 52 1.11.1.11 CO potent inhibitor 176 1.11.1.11 Co2+ inhibits the enzyme at 1-10 mM 23 1.11.1.11 Cu2+ inhibits the enzyme at 1 mM, complete inhibition at 5 mM 19 1.11.1.11 cyanide - 118 1.11.1.11 cysteine 50% inhibition at 5 mM 153 1.11.1.11 cysteine 100% inhibition at 5 mM 153 1.11.1.11 diethylenetriamine pentaacetic acid 9% inhibition at 5 mM 162991 1.11.1.11 dithioerythritol 67% inhibition at 0.05 mM 577 1.11.1.11 dithioerythritol 37% inhibition at 3 mM 577 1.11.1.11 dithiothreitol enzyme form C: 100% inhibition at 0.1 mM for 5 min, 57% of the inhibition can be recovered by filtration on Sephadex G-25 and a further 14% is recovered after the addition of homocystine at 2 mM 45 1.11.1.11 dithiothreitol 54% inhibition at 0.05 mM 45 1.11.1.11 dithiothreitol 40% inhibition at 3 mM 45 1.11.1.11 EDTA slight inhibition, but when the enzyme is incubated with EDTA 1 mM at 37°C for 3 min in the absence of sucrose and ferrous sulfate there is nearly complete inhibition 21 1.11.1.11 EDTA not inhibitory 21 1.11.1.11 EDTA 97% inhibition at 3 mM 21 1.11.1.11 EDTA 85.1% activity remaining at 10 mM 21 1.11.1.11 F- - 174 1.11.1.11 Fe3+ inhibits the enzyme at 1-10 mM 70 1.11.1.11 H2O2 wild-type enzyme has a half-time of inactivation of less than 10 sec. Triple mutant C26S/W35F/C126A retains 50% of the initial activity after H2O2 treatment for 3 min 22 1.11.1.11 H2O2 when inactivated by H2O2, heme is irreversibly cross-linked to the APX apoprotein. tsAPXW35F is inactivated in 3 min by H2O2. It is possible that tsAPXW35F is inactivated by adistinct mechanism because the heme can no longer be cross-linked to the enzyme 22 1.11.1.11 Hg2+ complete inhibition at 1 mM 33 1.11.1.11 Hg2+ inhibits the enzyme strongly at 1-10 mM 33 1.11.1.11 hydroxylamine recombinant enzyme 1: 74% inhibition at 1 mM and 100% inhibition at 10 mM, recombinant enzyme 2: 86% inhibition at 1 mM and 100% inhibition at 10 mM 85 1.11.1.11 hydroxylamine - 85 1.11.1.11 Hydroxyurea 26% inhibition at 1 mM 850 1.11.1.11 Hydroxyurea - 850 1.11.1.11 I- - 507 1.11.1.11 imidazole enzyme shows a decrease in its activity with increasing imidazole concentration, approximately 50% activity is lost in the presence of 0.8 M imidazole 470 1.11.1.11 iodoacetamide 30% inhibition at 1 mM, 65% inhibition at 5 mM 67 1.11.1.11 iodoacetamide 19% inhibition at 3 mM 67 1.11.1.11 iodoacetamide 92.5% activity remaining at 1 mM 67 1.11.1.11 iodoacetate potent inhibitor 93 1.11.1.11 iodoacetate not inhibitory 93 1.11.1.11 K+ inhibits the enzyme at 1-10 mM 39 1.11.1.11 KCN potent inhibitor 161 1.11.1.11 KCN enzyme form C: 74% inhibition at 0.1 mM 161 1.11.1.11 KCN 96.4% inhibition at 1 mM 161 1.11.1.11 KCN 87% inhibition at 1 mM 161 1.11.1.11 KCN complete inhibition at 0.05 mM 161 1.11.1.11 KCN 10% inhibition at 5 mM 161 1.11.1.11 KCN 95% inhibition at 0.1 mM 161 1.11.1.11 KCN recombinant enzyme 1: 69% inhibition at 0.1 mM and 100% inhibition at 0.5 mM, recombinant enzyme 2: 81% inhibition at 0.1 mM and 100% inhibition at 0.5 mM 161 1.11.1.11 KCN strong inhibition at 1 mM 161 1.11.1.11 KCN complete inhibition at 0.1 mM 161 1.11.1.11 KCN 100% inhibition at 0.5 mM 161 1.11.1.11 KCN - 161 1.11.1.11 KCN 1 mM, 69% residual activity, APX 1, 20% residual activity, APX 2 161 1.11.1.11 KCN 13.3% activity remaining at 1 mM 161 1.11.1.11 L-cysteine 28% inhibition at 3 mM 74 1.11.1.11 L-cysteine 51.8% activity remaining at 1 mM 74 1.11.1.11 Li+ - 152 1.11.1.11 Li+ inhibits the enzyme at 1-10 mM 152 1.11.1.11 Mersalyl 58% inhibition at 0.005 mM, 100% inhibition at 0.05 mM 1982 1.11.1.11 Mg2+ - 6 1.11.1.11 Mg2+ inhibits the enzyme at 1-10 mM 6 1.11.1.11 Mn2+ marked inhibition at 1 mM 11 1.11.1.11 Mn2+ inhibits the enzyme at 1-10 mM 11 1.11.1.11 additional information not inhibitory up to 100 mM: cyanide, azide, aminotriazole 2 1.11.1.11 additional information not inhibitory: alpha,alpha’-dipyridyl, EDTA 2 1.11.1.11 additional information tyrosine nitration has a negative impact. No effects are observed on the chaperone function and the oligomeric status of AtAPX1 2 1.11.1.11 N-ethylmaleimide 33% inhibition at 0.05 mM, 28% inhibition at 0.5 mM 49 1.11.1.11 Na+ inhibits the enzyme at 1-10 mM 59 1.11.1.11 Na2HAsO4 inhibition in the range of 0.01-0.5 mM 6567 1.11.1.11 NaN3 potent inhibitor 238 1.11.1.11 NaN3 enzyme form C: 27% inhibition at 5 mM 238 1.11.1.11 NaN3 91.5% inhibition at 1 mM 238 1.11.1.11 NaN3 13% inhibition at 5 mM 238 1.11.1.11 NaN3 complete inhibition at 1 mM 238 1.11.1.11 NaN3 17% inhibition at 1 mM, 87% inhibition at 10 mM 238 1.11.1.11 NaN3 strong inhibition at 5 mM 238 1.11.1.11 NaN3 complete inhibition at 4 mM 238 1.11.1.11 NaN3 80% inhibition at 1 mM 238 1.11.1.11 NaN3 - 238 1.11.1.11 Ni2+ - 38 1.11.1.11 Ni2+ below 0.01 mM, activation, inhibition above 38 1.11.1.11 Ni2+ inhibits the enzyme at 1-10 mM 38 1.11.1.11 p-Aminophenol time-dependent inhibition 7265 1.11.1.11 p-Aminophenol not inhibitory 7265 1.11.1.11 p-chloromercuribenzoate 95% inhibition at 0.05 mM 43 1.11.1.11 p-chloromercuribenzoate 87% inhibition at 0.005 mM, inactivation is partially reversible, 2-mercaptoethanol protects 43 1.11.1.11 p-chloromercuribenzoate 82% inhibition at 0.2 mM for 5 min 43 1.11.1.11 p-chloromercuribenzoate 84% inhibition at 0.2 mM for 5 min 43 1.11.1.11 p-chloromercuribenzoate 27% inhibition at 3 mM 43 1.11.1.11 p-chloromercuriphenyl sulfonic acid 100% inhibition at 0.05 mM, recombinant enzyme 1 and 2 2753 1.11.1.11 p-hydroxymercuribenzoate 43% inhibition at 0.005 mM, 100% inhibition at 0.05 mM 98 1.11.1.11 Pb2+ inhibits the enzyme at 1-5 mM, almost complete inhibition at 10 mM 139 1.11.1.11 phenylhydrazine a suicide substrate 398 1.11.1.11 reduced glutathione enzyme form C: 75% inhibition at 0.25 mM for 10 min 593 1.11.1.11 reduced glutathione 33% inhibition at 5 mM 593 1.11.1.11 reduced glutathione 25% inhibition at 3 mM 593 1.11.1.11 salicylic acid biologically active, reversible inhibition, 59% inhibition at 0.1 mM, 83% inhibition at 0.2 mM, 95% inhibition at 1 mM, the inhibition is not time-dependent 765 1.11.1.11 salicylic acid reducing substrate, not inhibitory 765 1.11.1.11 salicylic acid - 765 1.11.1.11 salicylic acid 98% inhibition at 0.5 mM 765 1.11.1.11 Sn2+ inhibits the enzyme at 1 mM, complete inhibition at 5 mM 413 1.11.1.11 Sodium azide 1 mM, 72% residual activity, APX 1, 55% residual activity, APX 2 447 1.11.1.11 Sodium azide 25.9% activity remaining at 1 mM 447 1.11.1.11 sodium nitroprusside partial 1483 1.11.1.11 Zn2+ - 14 1.11.1.11 Zn2+ leaves of plants grown with both low and high Zn show accumulation of lipid peroxides, ascorbate and dehydroascorbate, associated with a decrease in the activity of the enzyme 14 1.11.1.11 Zn2+ inhibits the enzyme at 1-10 mM 14