Application | Comment | Organism |
---|---|---|
drug development | the enzyme is a possible target for anti-parasite drug development | Trypanosoma cruzi |
Cloned (Comment) | Organism |
---|---|
gene HGPRTase, recombinant expression of His6-tagged enzyme and of nontagged enzyme in Escherichia coli strain BL21(DE3) | Trypanosoma cruzi |
Crystallization (Comment) | Organism |
---|---|
purified recombinant His6-tagged enzyme, mixing of 5 mg/ml protein in 20 mM Tris-HCl, 100 mM NaCl, pH 8.0, with reservoir solution containing 0.1 M MES, pH 6.5, and 12% w/v PEG 20000 at 20°C, X-ray diffraction structure determination and analysis at 2.65 A resolution | Trypanosoma cruzi |
Protein Variants | Comment | Organism |
---|---|---|
additional information | truncation of the C-terminal stretch of enzyme TcHPRTH6 enhances its catalytic efficiency | Trypanosoma cruzi |
General Stability | Organism |
---|---|
analysis of the stability of the variants in urea-induced unfolding experiments. Protein aggregation is taking place after dialysis or denaturant dilution, an indication of the existence of an irreversible phenomenon, precludes the derivation of thermodynamic state functions from the unfolding data. Nevertheless, the enzyme behaves as cooperative folding units when submitted to chemical denaturation, irreversible aggregation at 60°C within 10 min | Trypanosoma cruzi |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Trypanosoma cruzi |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate | Trypanosoma cruzi | - |
IMP + diphosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Trypanosoma cruzi | Q27796 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography and dialysis, recombinant nontagged enzyme from Escherichia coli by anion exchange chromatography, ammonium sulfate fractionation, dialysis, and gel filtration, both to over 95% purity | Trypanosoma cruzi |
Renatured (Comment) | Organism |
---|---|
although the enzyme protein irreversibly aggregates during unfolding, oligomerization is reversible and can be modulated by low concentrations of urea | Trypanosoma cruzi |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate | - |
Trypanosoma cruzi | IMP + diphosphate | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | when the C-terminal region, which is predicted as a disordered stretch, is excised by proteolysis, TcHPRT adopts a dimeric state, suggesting that the C-terminal region acts as a main guide for the quaternary arrangement. The C-terminal region exhibits a modulatory role on the enzyme, as attested by the enhanced activity observed for the dimeric form | Trypanosoma cruzi |
tetramer | the full-length enzyme form in solution adopts a stable and enzymatically active tetrameric form, exhibiting large intersubunit surfaces, two putative dimeric interfaces | Trypanosoma cruzi |
Synonyms | Comment | Organism |
---|---|---|
HGPRTase | - |
Trypanosoma cruzi |
hypoxanthine phosphoribosyl transferase | - |
Trypanosoma cruzi |
TcHPRT | - |
Trypanosoma cruzi |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Trypanosoma cruzi |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
60 | - |
analysis of the stability of the variants in temperature unfolding experiments. Protein aggregation is taking place after dialysis or denaturant dilution, an indication of the existence of an irreversible phenomenon, precludes the derivation of thermodynamic state functions from the unfolding data. But the enzyme behave as cooperative folding units when submitted to thermal denaturation. In particular, a qualitative comparison (a shift in the observed apparent Tm values) of thermal denaturation curves suggests that the His-tag present in TcHPRTH6 might enhance its thermostability by increasing the height of the activation barrier to the formation of aggregation-prone species. Nevertheless, when the enzyme is incubated for 10 min at 60°C, it irreversibly aggregates with a concomitant loss of enzymatic activity | Trypanosoma cruzi |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Trypanosoma cruzi |
General Information | Comment | Organism |
---|---|---|
metabolism | the metabolism of the protozoan parasite Trypanosoma cruzi depends on the salvage of exogenous purines for nucleotide synthesis. In this context, TcHPRT plays a key role in the survival of trypanosomes in their hosts | Trypanosoma cruzi |
physiological function | the hypoxanthine phosphoribosyl transferase (TcHPRT) is a critical enzyme in Trypanosoma cruzi for the survival of the parasite. TcHPRT catalyzes the transfer of a mono phosphorylated ribose from phosphoribosyl diphosphate (PRPP) to the purine ring | Trypanosoma cruzi |