Cloned (Comment) | Organism |
---|---|
the P135S mutant enzyme is expressed in HEK-293 cells | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
P135S | the mutant type 2 iodothyronine deiodinase has many type 1 iodothyronine deiodinase-like properties, a Km (L-thyroxine) in the micromolar range, ping-pong kinetics with dithiothreitol, and sensitivity to 6n-propylthiouracil in vitro. When the P135S mutant is expressed in HEK-293 cells and exposed to 2-200 pM free L-thyroxine, the rate of L-thyroxine to 3,5,3'-triiodo-L-thyronine conversion is identical with type 2 iodothyronine deiodinase and conversion is insensitive to 6n-propylthiouracil. Using glutathione as a cofactor in vitro results in a marked decrease in the Km (L-thyroxine) (as also occurs for type 1 iodothyronine deiodinase), it shows sequential kinetics with L-thyroxine and is sensitive to 6n-propylthiouracil but is resistant when HEK-293 cytosol is used as a cofactor | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | the wild type enzyme is insensitive to 6-propyl-2-thiouracil | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0000000017 | - |
L-thyroxine | mutant P135S type 2 iodothyronine deiodinase, with 20 mM glutathione as cofactor, in Tris-EDTA buffer (pH 7.5), at 37°C | Homo sapiens | |
0.0000000029 | - |
L-thyroxine | wild type type 2 iodothyronine deiodinase, with 20 mM glutathione as cofactor, in Tris-EDTA buffer (pH 7.5), at 37°C | Homo sapiens | |
0.0000000059 | - |
L-thyroxine | wild type type 2 iodothyronine deiodinase, with 20 mM dithiothreitol as cofactor, in Tris-EDTA buffer (pH 7.5), at 37°C | Homo sapiens | |
0.0000045 | - |
L-thyroxine | mutant P135S type 2 iodothyronine deiodinase, with 20 mM dithiothreitol as cofactor, in Tris-EDTA buffer (pH 7.5), at 37°C | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-thyroxine + AH2 | - |
Homo sapiens | 3,5,3'-triiodo-L-thyronine + iodide + A + H+ | - |
? |
Synonyms | Comment | Organism |
---|---|---|
type 2 iodothyronine deiodinase | - |
Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
dithiothreitol | 20 mM dithiothreitol is used in assay conditions | Homo sapiens | |
glutathione | 20 mM glutathione is used in assay conditions | Homo sapiens |