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)

This paper follows the development in the activity of the key enzymes of glycolysis and dehydrogenases of the pentose phosphate shunt throughout the in vitro growth and metacyclogenesis of two human strains of Leishmania infantum - one visceral (VL) and the other cutaneous (CL) - together with changes in the glucose, ammonium, and proton concentrations in the culture medium. In the first stage, ammonium was generated and no glucose was consumed. Later on, all the glucose was consumed and, finally, ammonium was generated again. The ammonium concentration increased 16- and 21-fold in cultures of VL and CL strains, respectively. The activities of the glycosomal enzymes hexokinase and phosphofructokinase differed in each strain, always being higher in CL than in VL and increasing throughout the culture period in CL while decreasing in VL. This probably indicates a different capability to adapt to the culture medium conditions. The activities of the pentose phosphate shunt enzymes examined indicate that 6-phosphogluconate dehydrogenase is possibly a rate-limiting enzyme for this pathway. Pyruvate kinase is a cytosolic control enzyme of glycolysis in trypanosomatids, and its activity decreased throughout the growth and differentiation of both strains of L. infantum, as occurs in other trypanosomatids. It was also observed that glucose catabolism was more active in the cutaneous strain than in the visceral one.
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PMID:Activity of key enzymes in glucose catabolism during the growth and metacyclogenesis of Leishmania infantum. 1009 12

The coding sequence for hexokinase enzyme was cloned from Leishmania major. The sequence was found to encode an enzyme with a molecular mass of 51.74 kDa. Amino acid sequence showed maximum homology with known trypanosome and plant hexokinases. It has a calculated isoelectric point of 8.46 and contains an N-terminal peroxisome-targeting signal, the characteristics frequently associated with glycosomal proteins. The sequence indicated the presence of conserved amino acid residues and motifs that are present in plant and mammalian hexokinases; these are apparently involved in the binding of different substrates. The L. major genome was found to have 2 copies of hexokinase coding sequences in tandem with an intergenic spacer of 2.58 kb. Both the genes in the hexokinase locus were transcribed as individual transcripts in a monocistronic form, having the same size as seen by Northern blot analysis. The hexokinase gene was transcribed in large amounts in the promastigote stage, whereas there is only weak expression in the amastigote stage as determined by RT-PCR analysis. Sequencing of hexokinase loci from different Leishmania species (e.g., L. donovani, L. infantum, L. tropica, and L. mexicana) revealed that the hexokinase locus is highly conserved at the DNA and protein levels among species of Leishmania compared with trypanosomes.
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PMID:Molecular characterization of the hexokinase gene from Leishmania major. 1653 44