Activating Compound | Comment | Organism | Structure |
---|---|---|---|
S-adenosyl-L-methionine | - |
Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Hg2+ | reactivity of Co(III) hCBS with HgCl2 is consistent with a loss of the cysteine(thiolate) ligand. 2-Mercaptoethanol is unable to reverse the Hg-induced ligand switch, in contrast to some other heme-thiolate proteins | Homo sapiens |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Co3+ | cobalt-substituted variant of hCBS, i.e. Co hCBS, in which CoPPIX replaces FePPIX, i.e. heme. Co(III) hCBS is a unique Co-substituted heme protein: the Co(III) ion is 6-coordinate, low-spin, diamagnetic, and bears a cysteine(thiolate) as one of its axial ligands. Electronic absorption and MCD spectra of the Co-substituted heme protein, overview. Co(III) hCBS is slowly reduced to Co(II) hCBS, which contains a 5-coordinate, low-spin, S = 1/2 Co-porphyrin that does not retain the cysteine(thiolate) ligand. This form of Co(II)hCBS binds NO but not CO. Co(II) hCBS is reoxidized in the air to form a new Co(III) form, which does not contain a cysteine(thiolate) ligand. Maintaining the native heme ligation motif of wild-type Fe hCBS (Cys/His) is essential in maintaining maximal activity in Co hCBS | Homo sapiens | |
Fe2+ | wild-type FePPIX, i.e. heme | Homo sapiens | |
additional information | maintaining the native heme ligation motif of wild-type Fe hCBS (Cys/His) is essential in maintaining maximal activity in Co hCBS | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
a cobalt-substituted variant of hCBS, i.e. Co hCBS, in which CoPPIX replaces FePPIX, i.e. heme | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | the enzyme performs L-cysteine sythesis from L-serine | Homo sapiens | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
CBS | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8.6 | - |
assay at | Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | - |
Homo sapiens | |
pyridoxal 5'-phosphate | - |
Homo sapiens |
General Information | Comment | Organism |
---|---|---|
metabolism | CBS is a key enzyme in the trans-sulfuration pathway and catalyzes the condensation of serine with homocysteine to produce cystathionine | Homo sapiens |