Activating Compound | Comment | Organism | Structure |
---|---|---|---|
ADP | 75.5% activation at 2 mM | Escherichia coli | |
ADP | 175.5% activity at 2 mM ADP | Escherichia coli | |
AMP | 71.8% activation at 2 mM | Escherichia coli | |
AMP | 171.8% activity at 2 mM AMP | Escherichia coli | |
ATP | 53.4% activation at 2 mM | Escherichia coli | |
ATP | 153.4% activity at 2 mM ATP | Escherichia coli |
Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli DH5alpha cells | Escherichia coli |
expression of the soluble enzyme in Escherichia coli strain DH5alpha | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2-mercaptoethanol | - |
Escherichia coli | |
beta-mercaptoethanol | 72% residual activity at 0.2% (v/v) | Escherichia coli | |
Ca2+ | 91.2% residual activity at 2 mM; slightly inhibitory | Escherichia coli | |
Co2+ | - |
Escherichia coli | |
Cu2+ | complete inhibition at 2 mM | Escherichia coli | |
dithiothreitol | 75.3% residual activity at 2 mM | Escherichia coli | |
DMSO | slightly inhibitory | Escherichia coli | |
DTT | - |
Escherichia coli | |
EDTA | 72.6% residual activity at 2 mM | Escherichia coli | |
Mn2+ | 67% residual activity at 2 mM | Escherichia coli | |
additional information | no or poor inhibition of the enzyme by Na+, Rb+, K+, Li+,, and Mg2+; the enzyme is not inhibited by thio-NAD+ and DMSO | Escherichia coli | |
NADPH | EcSTH activity is strongly inhibited by excess NADPH, but not by thio-NAD+; the enzyme is strongly inhibited by excess NADPH | Escherichia coli | |
Ni2+ | 7.4% residual activity at 2 mM | Escherichia coli | |
Zn2+ | 10.1% residual activity at 2 mM | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.06829 | - |
NADPH | at pH 7.5 and 35°C | Escherichia coli | |
0.0683 | - |
NADPH | pH 7.5, 35°C | Escherichia coli | |
0.1332 | - |
thio-NAD+ | pH 7.5, 35°C | Escherichia coli | |
0.1332 | - |
thio-NAD+ | at pH 7.5 and 35°C | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
soluble | - |
Escherichia coli | - |
- |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
additional information | not influenced by Na+, Rb+, K+, Li+, and Mg2+ | Escherichia coli |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
51500 | - |
x * 51500, calculated from amino acid sequence | Escherichia coli |
52000 | - |
x * 52000, SDS-PAGE | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
NADPH + NAD+ | Escherichia coli | - |
NADP+ + NADH | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Escherichia coli | P27306 | substrain MG1655, gene sth | - |
Purification (Comment) | Organism |
---|---|
TALON metal affinity resin column chromatography | Escherichia coli |
Storage Stability | Organism |
---|---|
25°C, purified enzyme, 25 days, 65% activity remaining | Escherichia coli |
4°C, purified enzyme, 25 days, stable | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
NADPH + NAD+ | - |
Escherichia coli | NADP+ + NADH | - |
r | |
NADPH + thio-NAD+ + H+[side 1] | - |
Escherichia coli | NADP+ + thio-NADH + H+[side 2] | - |
r | |
NADPH + thio-NAD+ + H+[side 1] | EcSTH has a 1.25fold preference for NADPH over thio-NAD+ | Escherichia coli | NADP+ + thio-NADH + H+[side 2] | - |
r |
Subunits | Comment | Organism |
---|---|---|
? | x * 52000, SDS-PAGE | Escherichia coli |
? | x * 51500, calculated from amino acid sequence | Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
energy-independent soluble pyridine nucleotide transhydrogenase | - |
Escherichia coli |
soluble pyridine nucleotide transhydrogenase | - |
Escherichia coli |
STH | - |
Escherichia coli |
UdhA | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
35 | - |
- |
Escherichia coli |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
20 | 45 | more than 70% activity between 20 and 45°C | Escherichia coli |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
4 | 50 | the enzyme retains 50% activity after 5 h at 50°C. The enzyme is stable at 4°C for 25 days and retains 65% activity at 25°C. The enzyme is rapidly inactivated at high temperatures, retaining 80%, 50% and 10% activity after incubation for 30 min at 50, 57 and 62°C, respectively | Escherichia coli |
50 | - |
purified enzyme, pH 7.5, 5h, 50% activity remaining, 80% activity remaining after 30 min | Escherichia coli |
57 | - |
purified enzyme, pH 7.5, 30 min, 50% activity remaining | Escherichia coli |
62 | - |
purified enzyme, pH 7.5, 30 min, 10% activity remaining | Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
167.9 | - |
NADPH | pH 7.5, 35°C | Escherichia coli | |
167.9 | - |
NADPH | at pH 7.5 and 35°C | Escherichia coli | |
259.5 | - |
thio-NAD+ | pH 7.5, 35°C | Escherichia coli | |
259.5 | - |
thio-NAD+ | at pH 7.5 and 35°C | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
- |
Escherichia coli |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
7 | 9 | more than 50% activity between pH 7.0 and 9.0 | Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
flavin | flavoprotein | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
evolution | two pyridine nucleotide transhydrogenases: the energy-independent soluble pyridine nucleotide transhydrogenase (STH or UdhA) (EC 1.6.1.1) and the membrane-bound, energy-dependent pyridine nucleotide transhydrogenase (TH or PntAB) (EC 1.6.1.2). PntAB is widely distributed in the mitochondria and some bacteria, while STH is found only in certain Gammaproteobacteria and gram-positive bacteria | Escherichia coli |
physiological function | the soluble pyridine nucleotide transhydrogenase, STH, is an energy-independent flavoprotein that directly catalyzes hydride transfer between NAD(H) and NADP(H) to maintain homeostasis of these two redox cofactors | Escherichia coli |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1940 | - |
thio-NAD+ | at pH 7.5 and 35°C | Escherichia coli | |
2460 | - |
NADPH | at pH 7.5 and 35°C | Escherichia coli |