Protein Variants | Comment | Organism |
---|---|---|
H61A | mutant enzyme H61A shows no dehydratase activity with 4a(R)-hydroxy-6(R)-methyltetrahydropterin. Mutant enzyme H79A shows no dehydratase activity with 4a(S)-hydroxy-6(R)-methyltetrahydropterin. The Km-value for 4a(S)-hydroxy-6(R)-methyltetrahydropterin is comparable to the Km-value of the wild type enzyme. The turnover number of the mutant enzyme H62A is 24% of that with the wild type enzyme for the 4a(R),6(S)-isomer and the 4a(S),6(R)-isomer | Rattus norvegicus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
diethyldicarbonate | inactivation is complete when about 1.2 His per subunit are derivatized | Rattus norvegicus | |
Quinoid 6(S)-propyldihydropterin | - |
Rattus norvegicus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0015 | - |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | wild type enzyme | Rattus norvegicus | |
0.0025 | - |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | mutant enzyme H79A | Rattus norvegicus | |
0.006 | - |
4a(R)-hydroxy-6(S)-methyltetrahydropterin | wild type enzyme | Rattus norvegicus | |
0.03 | - |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | mutant enzyme H62A | Rattus norvegicus | |
330 | - |
4a(R)-hydroxy-6(S)-methyltetrahydropterin | mutant enzyme H62A | Rattus norvegicus | |
390 | - |
4a(R)-hydroxy-6(S)-methyltetrahydropterin | mutant enzyme H61A | Rattus norvegicus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
11800 | - |
4 * 11800, mutant enzyme H61A, H62A and H79A, electrospray mass spectrometry | Rattus norvegicus |
11867 | - |
4 * 11867, wild type enzyme, electrospray mass spectrometry | Rattus norvegicus |
12000 | - |
4 * 12000, SDS-PAGE | Rattus norvegicus |
46000 | - |
HPLC gel filtration | Rattus norvegicus |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Rattus norvegicus | P61459 | - |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
4a-hydroxytetrahydrobiopterin = 6,7-dihydrobiopterin + H2O | His61 and His79 act as acid catalysts for the stereospecific elimination of the 4a(R)- and 4a(S)-hydroxyl groups, respectively. The role of His62 is primarily binding substrate with additional component of base catalysis | Rattus norvegicus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
liver | - |
Rattus norvegicus | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4a(R)-hydroxy-6(S)-methyltetrahydropterin | - |
Rattus norvegicus | quinoid 6(S)-methyldihydropterin | - |
? | |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | - |
Rattus norvegicus | quinoid 6(R)-methyldihydropterin | - |
? | |
4a-Hydroxy-6(S)-methyltetrahydropterin | - |
Rattus norvegicus | Quinoid 6(S)-methyldihydropterin | - |
? |
Subunits | Comment | Organism |
---|---|---|
tetramer | 4 * 12000, SDS-PAGE | Rattus norvegicus |
tetramer | 4 * 11800, mutant enzyme H61A, H62A and H79A, electrospray mass spectrometry | Rattus norvegicus |
tetramer | 4 * 11867, wild type enzyme, electrospray mass spectrometry | Rattus norvegicus |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
2.4 | - |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | mutant enzyme H62A | Rattus norvegicus | |
7.5 | - |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | mutant enzyme H79A | Rattus norvegicus | |
8.6 | - |
4a(R)-hydroxy-6(S)-methyltetrahydropterin | mutant enzyme H61A | Rattus norvegicus | |
8.9 | - |
4a(R)-hydroxy-6(S)-methyltetrahydropterin | mutant enzyme H62A | Rattus norvegicus | |
10 | - |
4a(R)-hydroxy-6(S)-methyltetrahydropterin | wild type enzyme | Rattus norvegicus | |
10 | - |
4a(S)-hydroxy-6(R)-methyltetrahydropterin | wild type enzyme | Rattus norvegicus |