Protein Variants | Comment | Organism |
---|---|---|
K94E | substitution prevents hexamer formation. Mutant does not display hysteresis | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.016 | - |
UDP-alpha-D-glucose | wild-type, pH 7.5, 25°C | Homo sapiens | |
0.269 | - |
UDP-alpha-D-glucose | mutant K94E, pH 7.5, 25°C | Homo sapiens | |
0.942 | - |
NAD+ | wild-type, pH 7.5, 25°C, Hill coefficient 0.74 | Homo sapiens | |
2.92 | - |
NAD+ | mutant K94E, pH 7.5, 25°C | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | O60701 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | enzyme displays hysteresis, observed as a lag in progress curves, and is sensitive to product inhibition during the lag. The inhibition results in a systematic decrease in steady-state velocity and makes the lag appear to have a second-order dependence on enzyme concentration.The lag is in fact due to a substrate and cofactor-induced isomerization of the enzyme. The cofactor binds to the enzyme:substrate complex with negative cooperativity, suggesting that the isomerization may be related to the formation of an asymmetric enzyme complex | Homo sapiens | ? | - |
? | |
UDP-alpha-D-glucose + 2 NAD+ + H2O | - |
Homo sapiens | UDP-alpha-D-glucuronate + 2 NADH + 2 H+ | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.012 | - |
UDP-alpha-D-glucose | mutant K94E, pH 7.5, 25°C | Homo sapiens | |
0.055 | - |
NAD+ | mutant K94E, pH 7.5, 25°C | Homo sapiens | |
1.4 | - |
UDP-alpha-D-glucose | wild-type, pH 7.5, 25°C | Homo sapiens | |
1.8 | - |
NAD+ | wild-type, pH 7.5, 25°C, Hill coefficient 0.74 | Homo sapiens |
General Information | Comment | Organism |
---|---|---|
physiological function | enzyme displays hysteresis, observed as a lag in progress curves, and is sensitive to product inhibition during the lag. The inhibition results in a systematic decrease in steady-state velocity and makes the lag appear to have a second-order dependence on enzyme concentration.The lag is in fact due to a substrate and cofactor-induced isomerization of the enzyme. The cofactor binds to the enzyme:substrate complex with negative cooperativity, suggesting that the isomerization may be related to the formation of an asymmetric enzyme complex. The hysteresis may be the consequence of a functional adaptation, by slowing the response of the enzyme to sudden increases in the flux of substrate, the other biochemical pathways that use this important metabolite will have a competitive edge | Homo sapiens |