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Literature summary for 2.4.2.8 extracted from

  • Jardim, A.; Ullman, B.
    The conserved serine-tyrosine dipeptide in Leishmania donovani hypoxanthine-guanine phosphoribosyltransferase is essential for catalytic activity (1997), J. Biol. Chem., 272, 8967-8973.
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
functional expression of wild-type enzyme and mutants in an enzyme-deficient Escherichia coli strain Leishmania donovani

Protein Variants

Protein Variants Comment Organism
additional information wild-type enzyme complements enzyme deficiency of the bacterial enzyme in Escherichia coli Leishmania donovani
S95A site-directed mutagenesis, dramatic reduction of catalytic activity, weak complementation of bacterial enzyme deficient strain Leishmania donovani
S95C site-directed mutagenesis, 2-3fold reduction of kcat, weak complementation of bacterial enzyme deficient strain Leishmania donovani
S95E site-directed mutagenesis, dramatic reduction of catalytic activity, no complementation of bacterial enzyme deficient strain Leishmania donovani
S95T site-directed mutagenesis, 2-3fold reduction of kcat, complementation of bacterial enzyme deficient strain Leishmania donovani
Y96F site-directed mutagenesis, dramatic reduction of catalytic activity, no complementation of bacterial enzyme deficient strain, 4-5fold decrease of Km value for 5-phosphoribosyl 1-diphosphate Leishmania donovani
Y96V site-directed mutagenesis, dramatic reduction of catalytic activity, no complementation of bacterial enzyme deficient strain, 4-5fold decrease of Km value for 5-phosphoribosyl 1-diphosphate Leishmania donovani

Inhibitors

Inhibitors Comment Organism Structure
diethyl dicarbonate alkylation of Arg155, complete inactivation at pH 9.0, pH dependent Leishmania donovani
additional information no effect of iodoacetate, phenylglyoxal, p-chloromercuribenzoate, acetic anhydride, ethyl dimethylaminopropylcarbodiimide/ammonium acetate, and diisopropyl fluorophosphate Leishmania donovani
Tetranitromethane complete inactivation at pH 9.0, pH dependent, modifies Tyr96 in the active site Leishmania donovani

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
additional information kinetics Leishmania donovani
additional information
-
additional information Km values of mutant enzymes for hypoxanthine, guanine, diphosphate, 5-phosphoribosyl 1-diphosphate, inosine monophosphate Leishmania donovani
0.005
-
guanine wild-type enzyme Leishmania donovani
0.0061
-
hypoxanthine wild-type enzyme Leishmania donovani
0.09
-
inosine monophosphate wild-type enzyme Leishmania donovani
0.103
-
diphosphate wild-type enzyme Leishmania donovani
0.134
-
5-phospho-alpha-D-ribose 1-diphosphate wild-type enzyme Leishmania donovani

Metals/Ions

Metals/Ions Comment Organism Structure
Mg2+
-
Leishmania donovani

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
guanine + 5-phospho-alpha-D-ribose 1-diphosphate Leishmania donovani
-
GMP + diphosphate
-
?
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate Leishmania donovani
-
IMP + diphosphate
-
?

Organism

Organism UniProt Comment Textmining
Leishmania donovani
-
-
-

Purification (Commentary)

Purification (Comment) Organism
recombinant from Escherichia coli Leishmania donovani

Reaction

Reaction Comment Organism Reaction ID
IMP + diphosphate = hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate essential role of Ser95-Tyr96 dyade in catalysis Leishmania donovani

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
additional information
-
kinetics Leishmania donovani

Storage Stability

Storage Stability Organism
-70°C, wild-type enzyme and mutants, except mutant S95C, stable up to 6 months Leishmania donovani

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
guanine + 5-phospho-alpha-D-ribose 1-diphosphate
-
Leishmania donovani GMP + diphosphate
-
?
guanine + 5-phospho-alpha-D-ribose 1-diphosphate
-
Leishmania donovani GMP + diphosphate
-
r
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate
-
Leishmania donovani IMP + diphosphate
-
?
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate
-
Leishmania donovani IMP + diphosphate
-
r
additional information kinetic study Leishmania donovani ?
-
?

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
assay at Leishmania donovani

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
8.54
-
hypoxanthine wild-type enzyme Leishmania donovani
36.3
-
5-phospho-alpha-D-ribose 1-diphosphate wild-type enzyme Leishmania donovani
41.3
-
guanine wild-type enzyme Leishmania donovani
77
-
inosine monophosphate wild-type enzyme Leishmania donovani
90
-
diphosphate wild-type enzyme Leishmania donovani

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8
-
assay at Leishmania donovani