Inhibitors | Comment | Organism | Structure |
---|---|---|---|
nitrite | nitrite is an excellent inhibitor of the chlorination activity of myeloperoxidase, there is progressive inhibition of enzyme activity with increasing concentration of nitrite up to a maximum of 80%. Upon addition of 100 mM L-tyrosine, enzyme activity is completely restored | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
- |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leukocyte | - |
Homo sapiens | - |
neutrophil | - |
Homo sapiens | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
Cl- + H2O2 + H+ | - |
Homo sapiens | HClO + H2O | - |
? | |
additional information | in the presence of physiological concentrations of nitrite and chloride, myeloperoxidase catalyzes little nitration of tyrosyl residues in a heptapeptide. However, the efficiency of nitration is enhanced at least 4fold by free tyrosine. Myeloperoxidase oxidizes free tyrosine to tyrosyl radicals that exchange with tyrosyl residues in peptides. These peptide radicals then couple with nitrogen dioxide to form 3-nitrotyrosyl residues | Homo sapiens | ? | - |
? | |
nitrite + L-tyrosine + H2O2 + H+ | poor substrate for myeloperoxidase, but free tyrosine facilitates nitration of tyrosyl residues by acting as a cosubstrate in the reaction | Homo sapiens | ? | - |
? | |
thiocyanate + H2O2 + H+ | - |
Homo sapiens | ? | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.7 | - |
nitrite | at 21°C in 50 mM sodium phosphate buffer, pH 7.4 | Homo sapiens | |
28.5 | - |
Cl- | at 21°C in 50 mM sodium phosphate buffer, pH 7.4 | Homo sapiens | |
30.5 | - |
thiocyanate | at 21°C in 50 mM sodium phosphate buffer, pH 7.4 | Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | - |
Homo sapiens |
IC50 Value | IC50 Value Maximum | Comment | Organism | Inhibitor | Structure |
---|---|---|---|---|---|
0.0013 | - |
at 21°C in 50 mM sodium phosphate buffer, pH 7.4 | Homo sapiens | nitrite |
General Information | Comment | Organism |
---|---|---|
physiological function | at sites of inflammation myeloperoxidase will nitrate proteins, even though nitrite is a poor substrate, because the co-substrate tyrosine will be available to facilitate the reaction | Homo sapiens |