Cloned (Comment) | Organism |
---|---|
- |
Homo sapiens |
Crystallization (Comment) | Organism |
---|---|
molecular dynamics simulations predict that K+ ions interact with residues Asp26 and/or Glu159. Crystal structure of BHMT bound to homocysteine confirms these sites of interaction and reveals further contacts between K+ ions and BHMT residues Gly27, Gln72, Gln247, and Gly298 | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
D26A | almost 3fold decrease in stimulation by K+ | Homo sapiens |
E159A | complete loss of activity | Homo sapiens |
E159Q | complete loss of activity | Homo sapiens |
G27S | no stimulation by K+ | Homo sapiens |
G28S | very small decrease in stimulation by K+ | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.015 | - |
L-homocysteine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
0.059 | - |
betaine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
0.075 | - |
betaine | wild-type, pH 7.5, 37°C | Homo sapiens | |
0.338 | - |
L-homocysteine | wild-type, pH 7.5, 37°C | Homo sapiens | |
2.3 | - |
L-homocysteine | wild-type, cosubstrate S-methylmethionine, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
3.4 | - |
S-methyl-L-methionine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
K+ | Km value around 0.1 mM. The presence of potassium ions lowers the apparent KM of the enzyme for homocysteine, but it does not affect the apparent KM for betaine or the apparent kcat for either substrate | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | Q93088 | - |
- |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
2 | - |
mutant G27S, pH 7.5, 37°C | Homo sapiens |
2 | - |
mutant G27S, presence of 150 mM K+, pH 7.5, 37°C | Homo sapiens |
5 | - |
mutant D26A, pH 7.5, 37°C | Homo sapiens |
18 | - |
mutant D26A, presence of 150 mM K+, pH 7.5, 37°C | Homo sapiens |
100 | - |
wild-type, pH 7.5, 37°C | Homo sapiens |
940 | - |
wild-type, presence of 150 mM K+, pH 7.5, 37°C | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-homocysteine + betaine | - |
Homo sapiens | L-methionine + dimethylglycine | - |
? | |
L-homocysteine + S-methyl-L-methionine | - |
Homo sapiens | 2 L-methionine | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0003 | - |
L-homocysteine | wild-type, cosubstrate S-methylmethionine, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
0.0044 | - |
S-methyl-L-methionine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
0.0298 | - |
betaine | wild-type, pH 7.5, 37°C | Homo sapiens | |
0.0367 | - |
L-homocysteine | wild-type, pH 7.5, 37°C | Homo sapiens | |
0.0378 | - |
L-homocysteine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
0.0422 | - |
betaine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.108 | - |
L-homocysteine | wild-type, pH 7.5, 37°C | Homo sapiens | |
0.386 | - |
betaine | wild-type, pH 7.5, 37°C | Homo sapiens | |
0.716 | - |
betaine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens | |
2.52 | - |
L-homocysteine | wild-type, presence of 150 mM KCl, pH 7.5, 37°C | Homo sapiens |