Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The yeast hexokinase isoenzymes PI and PII have been purified in large amounts (20 mg) from overproducing yeast strains. The purification procedures of hexokinase PI and PII include anion-exchange chromatography on DEAE-Sephacel and chromatofocusing on PBE 94, hydrophobic interaction chromatography on phenyl-Sepharose (necessary for the isolation of the isoenzyme PI); in the final step either a Mono Q HR 5/5 or a Fractogel EMD TMAE 650(S) column was used. Hexokinase preparations were characterized before crystallization by chromatofocusing on a Mono P HR 5/20 FPLC column, where different forms of hexokinase can be rapidly distinguished by their elution behaviour. From both purified hexokinase PI and PII, large crystals were grown that diffract X-rays to high resolution.
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PMID:Purification and crystallization of yeast hexokinase isoenzymes. Characterization of different forms by chromatofocusing. 178 64

A full-length hexokinase cDNA was cloned from Solanum chacoense, a wild relative of the cultivated potato. Analysis of the predicted primary sequence suggested that the protein product, ScHK2, may be targeted to the secretory pathway and inserted in the plant plasma membrane, facing the cytosol. ScHK2 was expressed as a hexahistidine-tagged protein in Escherichia coli. Expression conditions for this construct were optimized using a specific anti-hexokinase polyclonal anti-serum raised against a truncated version of ScHK2. The full-length recombinant protein was purified to electrophoretic homogeneity using immobilized metal ion affinity chromatography followed by anion exchange chromatography on Fractogel EMD DEAE-650 (S). The purified enzyme had a specific activity of 5.3 micromol/min/mg protein. Its apparent Kms for glucose (23 microM), mannose (30 microM), fructose (5.2 mM), and ATP (61 microM) were in good agreement with values found in the literature for other plant hexokinases. Hexahistidine-tagged ScHK2 was highly sensitive to pH variations between 7.7 and 8.7. It was inhibited by ADP and insensitive to glucose-6-phosphate. These findings constitute the first kinetic characterization of a homogeneous plant hexokinase preparation. The relevance of ScHK2 kinetic properties is discussed in relation to the regulation of hexose metabolism in plants.
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PMID:Cloning, expression, purification, and properties of a putative plasma membrane hexokinase from Solanum chacoense. 1637 70