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)

Activity of hexokinase, phosphorylase, glucoso-6-phosphate dehydrogenase lactate-dehydrogenase was studied in liver slices, homogenate and supernatant fraction after freezing at a rate of 1 degree/min down to -30 degrees C. The enzyme activity in homogenate and supernatant fraction does not change after freezing. A significant reduction in the activity of most enzymes that is followed by an increase in their activity in the freezing medium was observed in the experiments. Cryoprotectant polyethylene glycol, mol. wt. 300 and 1,000 (PEG-300 and PEG-1,000), partially prevents the observed changes in the enzyme activity; PEG-1,000 is more effective than PEG-300. Experimental results show that the main reason for the reduction of the enzyme activity observed after freezing the tissue slices is a decrease in the volume of intracellular enzyme proteins due to their leakage from the injured cellular elements into the exocellular medium.
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PMID:[Activity of carbohydratephosphate metabolism enzymes in liver slices after freezing and thawing]. 88 19

This work shows that the enzyme membrane reactor offers the opportunity to carry out the enzymatic regeneration of ATP providing continuous operation with high performance. In this system, the coenzyme is immobilized on a water-soluble polymer. These high-molecular weight derivates are entrapped within an ultrafiltration membrane together with the enzymes for production of regeneration. Several polymer derivatives of ATP have been prepared for this immobilization technique. Coenzymatic activity of these derivatives was studied with several enzymes for both ATP-requiring and ATP-regenerating reactions. PEG-N6-aminohexyl-ATP was selected as the appropriate coenzyme for operating the enzyme membrane reactor. Acetate kinase was the only enzyme providing enough activity for regeneration. Production of glucose-6-phosphate is cited as the first example. The kinetics of acetate kinase and hexokinase were examined and used to choose the operating conditions of the process. The process operated continuously for more than 1 month. With a mean conversion of 80%, the space-time yield amounted to 348 g glucose-6-phosphate/L d. The cycle number of ATP was estimated as 20, 000 mol/mol. With the continuous production of gamma-glutamylcysteine and NADP, the feasibility of the system was proven.
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PMID:Continuous regeneration of ATP in enzyme membrane reactor for enzymatic syntheses. 1858 29