Activating Compound | Comment | Organism | Structure |
---|---|---|---|
N-ethylmaleimide | slight stimulation, 117% of activity | Rattus norvegicus |
General Stability | Organism |
---|---|
addition of pyridoxal 5'-phosphate is essential for activity after ammonium sulfate fractionation | Rattus norvegicus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
aminooxyacetic acid | 1 mM, complete inhibition of the three isoenzymes | Rattus norvegicus | |
EDTA | 1 mM, 92% remaining activity | Rattus norvegicus | |
hydroxylamine | 1 mM, complete inhibition of the three isoenzymes | Rattus norvegicus | |
KCN | 1 mM, 38% remaining activity for CAT 1, less efficient inhibitor for CAT-IIA and CAT-IIB | Rattus norvegicus | |
MgCl2 | 1 mM, 90% remaining activity | Rattus norvegicus | |
additional information | iodoacetic acid and dithiothreitol, at 1 mM concentration, are poor inhibitors | Rattus norvegicus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.41 | - |
2-oxoglutarate | isoenzyme CAT-IIA, pH 7.0, 35°C | Rattus norvegicus | |
0.5 | - |
2-oxoglutarate | isoenzyme CAT-IIB, pH 7.0, 35°C | Rattus norvegicus | |
0.67 | - |
S-(4-Bromophenyl)-L-cysteine | isoenzyme CAT-IIA, pH 7.0, 35°C | Rattus norvegicus | |
1 | - |
S-(4-Bromophenyl)-L-cysteine | isoenzyme CAT-I, pH 7.0, 35°C | Rattus norvegicus | |
1.33 | - |
2-oxoglutarate | isoenzyme CAT-I, pH 7.0, 35°C | Rattus norvegicus | |
2 | - |
S-(4-Bromophenyl)-L-cysteine | isoenzyme CAT-IIB, pH 7.0, 35°C | Rattus norvegicus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cytosol | 64% of transaminase activity in cytosol | Rattus norvegicus | 5829 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Ca2+ | slight stimulation | Rattus norvegicus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
64000 | - |
isoenzyme CAT-I | Rattus norvegicus |
64000 | - |
CAT-IIA, CAT-IIB have the same molecular weight, all of them determined by gel filtration | Rattus norvegicus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | Rattus norvegicus | isoenzyme CAT-I may be involved in in vivo transamination of cysteine conjugates in rat liver, value of reverse reaction is 5 times lower than forward reaction by CAT-I, forward and reverse reaction at similar rates for CAT-IIA and CAT-IIB | ? | - |
? | |
S-(4-bromophenyl)-L-cysteine + 2-oxoglutarate | Rattus norvegicus | highest activity with all three isoenzymes: CAT-I, CAT-IIA, CAT-IIB | S-(4-bromophenyl)-3-thiopyruvate + L-glutamate | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Rattus norvegicus | - |
CAT-1 partially purified, obtained with isoenzymes CAT-IIA, CAT-IIB | - |
Purification (Comment) | Organism |
---|---|
ammonium sulfate partial purification, followed by DEAE-cellulose, where it is separated from CAT IIa and CAT-IIB, later on, hydroxyapatite column and gel filtration steps | Rattus norvegicus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
liver | - |
Rattus norvegicus | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.263 | - |
isoenzyme CAT-IIB, pH 7.0, 35°C | Rattus norvegicus |
0.297 | - |
isoenzyme CAT-IIA, pH 7.0, 35°C | Rattus norvegicus |
0.423 | - |
isoenzyme CAT-I, pH 7.0, 35°C | Rattus norvegicus |
Storage Stability | Organism |
---|---|
-20°C, 200 mM phosphate buffer pH 7.4, 50% loss of activity in two weeks | Rattus norvegicus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-aspartic acid + 2-oxoglutarate | reactivity of isozymes: less than 5% for CAT-I, 15% for CAT-IIA, 42% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | oxaloacetate + L-glutamate | - |
? | |
L-cysteine sulfinic acid + 2-oxoglutarate | reactivity of isozymes: less than 5% for CAT-I, 7% for CAT-IIA, 76% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | 2-oxo-3-sulfinopropionate + L-glutamate | - |
? | |
L-kynurenine + 2-oxoglutarate | reactivity of isozymes: 7% for CAT-I, 6% for CAT-IIA, 12% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | L-glutamate + 4-(2-aminophenyl)-2,4-dioxobutanoate | - |
? | |
additional information | 2-oxobutanoate, 2-oxosuccinate and pyruvate exhibit about 3% of activity compared to alpha-ketoglutarate | Rattus norvegicus | ? | - |
? | |
additional information | glyoxylic acid, S-ethyl-L-cysteine, S-2-propyl-L-cysteine, S-cyclohexyl-L-cysteine, S-(2-chloroethyl)-L-cysteine, S-phenyl-L-cysteine sulfoxide are not substrates, negligible activity with other amino acids e.g. L-leucine, L-configuration is essential | Rattus norvegicus | ? | - |
? | |
additional information | isoenzyme CAT-I may be involved in in vivo transamination of cysteine conjugates in rat liver, value of reverse reaction is 5 times lower than forward reaction by CAT-I, forward and reverse reaction at similar rates for CAT-IIA and CAT-IIB | Rattus norvegicus | ? | - |
? | |
S-(1-butyl)-L-cysteine + 2-oxoglutarate | reactivity of isozymes: 23% for CAT-I, 30% for CAT-IIA, 33% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | S-(1-butyl)-3-thiopyruvate + L-glutamate | - |
? | |
S-(1-propyl)-L-cysteine + 2-oxoglutarate | reactivity of isozymes: 16% for CAT-I, 13% for CAT-IIA, 14% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | S-(1-propyl)-3-thiopyruvate + L-glutamate | - |
? | |
S-(4-bromophenyl)-L-cysteine + 2-oxoglutarate | highest activity with all three isoenzymes: CAT-I, CAT-IIA, CAT-IIB | Rattus norvegicus | S-(4-bromophenyl)-3-thiopyruvate + L-glutamate | - |
r | |
S-(4-bromophenyl)-L-cysteine + 4-methylsulfanyl-2-oxobutanoate | 21% of activity compared to 2-oxoglutarate | Rattus norvegicus | S-(4-bromophenyl)-3-thiopyruvate + methionine | - |
? | |
S-benzyl-L-cysteine + 2-oxoglutarate | reactivity of isozymes: 19% for CAT-I, 16% for CAT-IIA, 20% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | S-benzyl-3-thiopyruvate + L-glutamate | - |
? | |
S-phenyl-L-cysteine + 2-oxoglutarate | reactivity of isozymes: 36% for CAT-I, 24% for CAT-IIA, 34% for CAT-IIB, activity compared to S-(4-bromophenyl)-L-cysteine | Rattus norvegicus | S-phenyl-3-thiopyruvate + L-glutamate | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Rattus norvegicus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
most active in Tris-acetate buffer, other buffers inhibit enzyme activity by 50-90% in comparison with this buffer | Rattus norvegicus |
7 | - |
isoenzymes CAT-I, CAT-IIA, CAT-IIB | Rattus norvegicus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | may be a coenzyme, indicated by inhibitory effects of carbonyl reagents | Rattus norvegicus |