Hexose phosphorylation by the ruminal bacterium Selenomonas ruminantium. 1996

S A Martin
Department of Animal and Dairy Science, University of Georgia, Athens 30602-2771, USA.

Three strains of Selenomonas ruminantium (D, GA192, and H18) were surveyed for phosphorylation of D-glucose and 2-deoxyglucose by phosphoenolpyruvate and ATP. Cells of all three strains that had been treated with toluene had high rates of hexose phosphorylation with either phosphoryl donor; this activity was constitutive in strain D. Glucose phosphorylation that was dependent on phosphoenolpyruvate was maximal at pH 7.2, remained fairly high at pH 6.5, but decreased (> or = 65%) at pH 5.0 for all strains. Cell extracts were used to evaluate the involvement of soluble kinases in 2-deoxyglucose phosphorylation. Both glucose and 2-deoxyglucose were phosphorylated by ATP, but phosphorylation of either hexose was negligible with phosphoenolpyruvate in each bacterium. Because phosphoenolpyruvate could not serve as a phosphoryl donor, the activity dependent on phosphoenolpyruvate in cells treated with toluene might have been due to a phosphotransferase system associated with the membrane. Unlabeled 2-deoxyglucose was a strong inhibitor (> or = 59%) of [14C]glucose phosphorylation with ATP by cell extracts of all S. ruminantium strains, and unlabeled glucose was a strong inhibitor (> or = 78%) of [14C]2-deoxyglucose phosphorylation with ATP. Based on Lineweaver-Burk kinetics, 2-deoxyglucose was a competitive inhibitor of initial rates of kinase activity in strains D, GA192, and H18. These results collectively suggest that glucose phosphorylation with phosphoenolpyruvate and 2-deoxyglucose phosphorylation with ATP are common traits in these strains of S. ruminantium.

UI MeSH Term Description Entries
D010728 Phosphoenolpyruvate A monocarboxylic acid anion derived from selective deprotonation of the carboxy group of phosphoenolpyruvic acid. It is a metabolic intermediate in GLYCOLYSIS; GLUCONEOGENESIS; and other pathways.
D010766 Phosphorylation The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety. Phosphorylations
D003847 Deoxyglucose 2-Deoxy-D-arabino-hexose. An antimetabolite of glucose with antiviral activity. 2-Deoxy-D-glucose,2-Deoxyglucose,2-Desoxy-D-glucose,2 Deoxy D glucose,2 Deoxyglucose,2 Desoxy D glucose
D005941 Glucokinase A group of enzymes that catalyzes the conversion of ATP and D-glucose to ADP and D-glucose 6-phosphate. They are found in invertebrates and microorganisms, and are highly specific for glucose. (Enzyme Nomenclature, 1992) EC 2.7.1.2.
D005947 Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D006089 Gram-Negative Anaerobic Bacteria A large group of anaerobic bacteria which show up as pink (negative) when treated by the Gram-staining method. Gram Negative Anaerobic Bacteria
D006863 Hydrogen-Ion Concentration The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000255 Adenosine Triphosphate An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter. ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001667 Binding, Competitive The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements. Competitive Binding

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