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Literature summary extracted from

  • Kroschewski, H.; Ortner, S.; Steipe, B.; Scheiner, O.; Wiedermann, G.; Duchene, M.
    Differences in substrate specificity and kinetic properties of the recombinant hexokinases HXK1 and HXK2 from Entamoeba histolytica (2000), Mol. Biochem. Parasitol., 105, 71-80.
    View publication on PubMed

Activating Compound

EC Number Activating Compound Comment Organism Structure
2.7.1.1 glucose 6-phosphate recombinant HXK1: at 10 mM 13% activation, at 20 mM 31% activation, recombinant HXK2: at 10 mM 23% activation, at 20 mM 48% activation Entamoeba histolytica

Cloned(Commentary)

EC Number Cloned (Comment) Organism
2.7.1.1 cDNAs coding for HXK1 and HXK2 are cloned and expressed in Escherichia coli K38 Entamoeba histolytica

Protein Variants

EC Number Protein Variants Comment Organism
2.7.1.1 additional information HXK1 mutants with modified active sites Entamoeba histolytica

Inhibitors

EC Number Inhibitors Comment Organism Structure
2.7.1.1 adenosine at 10 mM, recombinant HXK1: 36% inhibition, recombinant HXK2: 5% inhibition Entamoeba histolytica
2.7.1.1 ADP strong, recombinant HXK1 and 2, HXK1 is more sensitive to inhibition than HXK2 Entamoeba histolytica
2.7.1.1 AMP strong, recombinant HXK1 and 2, HXK1 is more sensitive to inhibition than HXK2 Entamoeba histolytica
2.7.1.1 additional information not inhibited by D-glucose 6-phosphate Entamoeba histolytica

KM Value [mM]

EC Number KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
2.7.1.1 additional information
-
 additional information of HXK1 mutants with modified active site Entamoeba histolytica
2.7.1.1 0.047
-
 D-glucose recombinant HXK2, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 0.059
-
 D-glucose recombinant HXK1, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 0.183
-
 ATP recombinant HXK1, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 0.654
-
 ATP recombinant HXK2, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 1.03
-
 D-mannose recombinant HXK1, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 2
-
 D-mannose recombinant HXK2, at 30°C, pH 8 Entamoeba histolytica

Natural Substrates/ Products (Substrates)

EC Number Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
2.7.1.1 D-glucose + ATP Entamoeba histolytica initial enzyme of glycolysis D-glucose 6-phosphate + ADP
-
 ?
2.7.1.1 D-glucose + ATP Entamoeba histolytica at high energy charge HXK1 may be involved in glycolysis and in some biosynthetic processes, e.g. phosphorylating mannose or glucose for the later integration into membrane components, at low energy charge HXK1 could be inhibited by AMP and ADP, and HXK2 would be more active and could keep up glucokinase activity for glycolysis D-glucose 6-phosphate + ADP
-
 ?
2.7.1.1 D-glucose + ATP Entamoeba histolytica SFL-3 initial enzyme of glycolysis D-glucose 6-phosphate + ADP
-
 ?

Organism

EC Number Organism UniProt Comment Textmining
2.7.1.1 Entamoeba histolytica
-
 2 isoenzymes: HXK1 and HXK2
-
2.7.1.1 Entamoeba histolytica SFL-3
-
 2 isoenzymes: HXK1 and HXK2
-

Purification (Commentary)

EC Number Purification (Comment) Organism
2.7.1.1 recombinant HXK1 and HXK2, expressed in Escherichia coli K38 Entamoeba histolytica

Specific Activity [micromol/min/mg]

EC Number Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
2.7.1.1 additional information
-
-
 Entamoeba histolytica

Substrates and Products (Substrate)

EC Number Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
2.7.1.1 D-glucose + ATP good substrate Entamoeba histolytica ADP + D-glucose 6-phosphate
-
 ?
2.7.1.1 D-glucose + ATP good substrate Entamoeba histolytica SFL-3 ADP + D-glucose 6-phosphate
-
 ?
2.7.1.1 D-glucose + ATP initial enzyme of glycolysis Entamoeba histolytica D-glucose 6-phosphate + ADP
-
 ?
2.7.1.1 D-glucose + ATP at high energy charge HXK1 may be involved in glycolysis and in some biosynthetic processes, e.g. phosphorylating mannose or glucose for the later integration into membrane components, at low energy charge HXK1 could be inhibited by AMP and ADP, and HXK2 would be more active and could keep up glucokinase activity for glycolysis Entamoeba histolytica D-glucose 6-phosphate + ADP
-
 ?
2.7.1.1 D-glucose + ATP initial enzyme of glycolysis Entamoeba histolytica SFL-3 D-glucose 6-phosphate + ADP
-
 ?
2.7.1.1 D-mannose + ATP HXK1: good substrate, HXK2: much lower phosphorylation rate than of HXK1 Entamoeba histolytica ADP + D-mannose 6-phosphate
-
 ?
2.7.1.1 D-mannose + ATP HXK1: good substrate, HXK2: much lower phosphorylation rate than of HXK1 Entamoeba histolytica SFL-3 ADP + D-mannose 6-phosphate
-
 ?
2.7.1.1 additional information not: fructose Entamoeba histolytica ?
-
 ?
2.7.1.1 additional information not: D-galactose Entamoeba histolytica ?
-
 ?
2.7.1.1 additional information not: fructose Entamoeba histolytica SFL-3 ?
-
 ?
2.7.1.1 additional information not: D-galactose Entamoeba histolytica SFL-3 ?
-
 ?

Subunits

EC Number Subunits Comment Organism
2.7.1.1 ? x * about 50000, HXK1 and 2 Entamoeba histolytica

Temperature Optimum [°C]

EC Number Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
2.7.1.1 30
-
 assay at Entamoeba histolytica
2.7.1.1 45
-
 recombinant HXK1 and 2 Entamoeba histolytica

Temperature Range [°C]

EC Number Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
2.7.1.1 25
-
 HXK1: 40% of maximum activity, HXK2: 28% of maximum activity Entamoeba histolytica
2.7.1.1 37
-
 HXK1: 78% of maximum activity, HXK2: 69% of maximum activity Entamoeba histolytica

Turnover Number [1/s]

EC Number Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
2.7.1.1 195
-
 D-glucose recombinant HXK2, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 284
-
 D-glucose recombinant HXK1, at 30°C, pH 8 Entamoeba histolytica

pH Optimum

EC Number pH Optimum Minimum pH Optimum Maximum Comment Organism
2.7.1.1 8
-
 assay at Entamoeba histolytica
2.7.1.1 8 9 recombinant HXK1 and 2: maximum activity, HXK1 is clearly more active than HXK2 around pH 6-7.5 Entamoeba histolytica

pH Range

EC Number pH Minimum pH Maximum Comment Organism
2.7.1.1 6 9 recombinant HXK1 and 2, significant activity between the range Entamoeba histolytica

pH Stability

EC Number pH Stability pH Stability Maximum Comment Organism
2.7.1.1 4
-
 recombinant HXK1 and 2 precipitate and lose all activity Entamoeba histolytica

Cofactor

EC Number Cofactor Comment Organism Structure
2.7.1.1 ATP
-
 Entamoeba histolytica

Ki Value [mM]

EC Number Ki Value [mM] Ki Value maximum [mM] Inhibitor Comment Organism Structure
2.7.1.1 0.00065
-
 AMP recombinant HXK1, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 0.031
-
 AMP recombinant HXK2, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 0.036
-
 ADP recombinant HXK1, at 30°C, pH 8 Entamoeba histolytica
2.7.1.1 0.193
-
 ADP recombinant HXK2, at 30°C, pH 8 Entamoeba histolytica