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

Polyphosphate glucokinase (EC 2.7.1.63, polyphosphate:glucose phosphotransferase) was covalently coupled to collagen-coated silica gel beads. The immobilized enzyme, as a packed-bed reactor, was used to determine glucose in serum and other samples. The method was based on a spectrophotometric measurement of NADPH produced by two consecutive reactions, similar to the hexokinase method. The described approach takes advantage of the greater stability of polyphosphate compared to that of ATP, the greater specificity of polyphosphate glucokinase versus that of hexokinase, and the reusability of the immobilized enzyme. Linearity, precision, and accuracy of the method were tested and found to be very good. The results were linear between 10 and 50 nmol of glucose in a 50-microliter sample and the coefficient of variation was less than 4% in five successive determinations. The recovery of glucose was about 100% after calibration of the method. The results of the measurements correlated well with those obtained with soluble polyphosphate glucokinase (r = 0.997, y = 1.036x - 0.016). The immobilized-enzyme reactor showed good operational stability during a month of use, losing about 12% of its initial activity.
 ...
PMID:Glucose determination using immobilized polyphosphate glucokinase. 166 65

The peculiarities of glucose metabolism were studied in typical representatives of coryneform bacteria, and its relation to inorganic polyphosphate metabolism was shown. The activity of the first two enzymes in the pentose pathway was found to be low. The key enzymes of glycolysis were detected, viz. fructose-1,6-diphosphate aldolase and 3-phosphoglyceraldehyde dehydrogenase. The second enzyme was more active in Nocardia sp. B-293 similar in its properties to Nocardia erythropolis as compared to the enzymes of the pentose shunt. The existence of polyphosphate glucokinase more active than ATP-dependent hexokinase is indicative of inorganic polyphosphates being involved in the metabolism of the above microorganisms.
 ...
PMID:[Carbohydrate metabolic characteristics of coryneform bacteria]. 677 12

Polyphosphate glucokinase from Mycobacterium tuberculosis catalyzes the phosphorylation of glucose using polyphosphate or ATP as the phosphoryl donor. The M. tuberculosis H37Rv gene encoding this enzyme has been cloned, sequenced, and expressed in Escherichia coli. The gene contains an open reading frame for 265 amino acids with a calculated mass of 27,400 daltons. The recombinant polyphosphate glucokinase was purified 189-fold to homogeneity and shown to contain dual enzymatic activities, similar to the native enzyme from H37Ra strain. The high G+C content in the codon usage (64.5%) of the gene and the absence of an E. coli-like promoter consensus sequence are consistent with other mycobacterial genes. Two phosphate binding domains conserved in the eukaryotic hexokinase family were identified in the polyphosphate glucokinase sequence, however, "adenosine" and "glucose" binding motifs were not apparent. In addition, a putative polyphosphate binding region is also proposed for the polyphosphate glucokinase enzyme.
 ...
PMID:Cloning, expression, and characterization of polyphosphate glucokinase from Mycobacterium tuberculosis. 861 63

The obligate destructor of ethylene diamine tetraacetate--a culture of Chelativorans oligotrophicus LPM-4--did not grow on a medium with glucose, but it was good to use it under cultivation on a mixture with EDTA after considerable decrease of the EDTA concentration in the medium (two-phase growth). Strong inhibition of hexokinase and glucose 6-phosphate dehydrogenase in cell exracts 4 mM EDTA was revealed. Using EDTA, cells accumulated polyphosphates whose rate decreased during glucose utilization phase. High activities of polyphosphate biosynthesis ferments (adenylat kinase and polyphosphate kinase) were distinguished during the first phase of the cultivation; considerable decrease of them and increase of polyphosphate glucokinase were found during the second phase of the cultivation. This points to the possible participating of polyphosphates in glucose metabolism as a supplementary energy source.
 ...
PMID:[Metabolism characteristics of Chelativorans oligotrophicus by two-phase growth on the mixture of EDTA and glucose]. 1984 87