EC Number   |
Inhibitors |
Structure  |
|---|
    6.3.4.2 | more |
enzyme loses activity at ionic strengths higher than 0.4 M |
 |
| 6.3.4.2 | more |
GTP analogues inhibite NH3-and Gln-dependent CTP-formation, often in a cooperative manner, to a similar extent as they activate it with IC50 values of 0.2-0.5 mM, the inhibition appears to be due solely to the purine base, binding structures and kinetics, overview. Inhibitor structure-activity study, overview |
|
| 6.3.4.2 | more |
incubation of EcCTPS modified by CysNO and HcyNO with 5 mM DTT for 30 min at 37°C reveals that 88% and 97%, respectively, of the original activity can be recovered; it is shown that in the presence of 1 mM Gln, S-nitroso-L-cysteine reduces the enzymatic activity by 88% and by 32% in the presence of 10 mM Gln. Similar studies with S-nitroso-L-homocysteine result in reduction of the activity by 43% and 19%, respectively. The results suggest that the substrate Gln competitively protects the active site of EcCTPS from the modification with S-nitroso-L-cysteine and S-nitroso-L-homocysteine.; no inhibition by S-nitrosoglutathione presumably due to its inability to enter the actve site of the enzyme |
|
| 6.3.4.2 | more |
inhibition by xanthine and derivatives, no inhibition by allantoin, an intact purine ring with anionic character favors inhibition. In general, methylation of the purine does not significantly affect inhibition |
|
| 6.3.4.2 | Mn2+ |
above 2 mM |
  |
| 6.3.4.2 | Zn2+ |
inhibition is reversed by EDTA, in presence of dithiothreitol inhibition at concentrations below 0.2 mM |
|
| 6.3.4.2 | Cu2+ |
inhibition is not reversed by EDTA, in presence of dithiothreitol inhibition at concentrations below 0.2 mM |
|
| 6.3.4.2 | Co2+ |
above 2 mM |
|
| 6.3.4.2 | GTP |
inhibition of N4-OH-CTP synthesis |
|
| 6.3.4.2 | GTP |
inhibition of glutamine-dependent CTP formation above 0.15 mM, inhibition of glutamine-dependent CTP formation in a concentration-dependent manner |
|
