Measurement of the Activity of the Hexose Monophosphate Pathway of Glucose Metabolism with the Use of [18O]Glucose. Variations in Its Activity in Escherichia coli with Growth Conditions*

Biochemistry ◽  
1967 ◽  
Vol 6 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Peter Model ◽  
David Rittenberg
Keyword(s):  
Escherichia Coli ◽  
Glucose Metabolism ◽  
Growth Conditions ◽  
Hexose Monophosphate ◽  
Hexose Monophosphate Pathway

scholarly journals Effect of dithiocyano-methane on hexose monophosphate pathway in the respiratory metabolism of Escherichia coli

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yanfeng Chen ◽  
Wenjie Ke ◽  
Huabin Qin ◽  
Siwei Chen ◽  
Limei Qin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Control Group ◽  
Respiratory Metabolism ◽  
Hexose Monophosphate ◽  
Hexose Monophosphate Pathway ◽  
Response To Stress ◽  
Glucose Decomposition ◽  
Decomposition Pathway ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract This paper studied the inhibitory effects of dithiocyano-methane (DM) on the glucose decomposition pathway in the respiratory metabolism of Escherichia coli. We investigated the effects of DM on the activities of key enzymes (ATPase and glucose-6-phosphate dehydrogenase, G6PDH), the levels of key product (nicotinamide adenosine denucleotide hydro-phosphoric acid, NADPH), and gene expression in the hexose monophosphate pathway (HMP). The results showed that the minimum inhibitory concentration (MIC) and the minimum bactericide concentration (MBC) of DM against the tested strains were 5.86 mg/L and 11.72 mg/L, respectively. Bacteria exposed to DM at MIC demonstrated an increase in bacterial ATPase and G6PDH activities, NADPH levels, and gene expression in the HMP pathway compared to bacteria in the control group, which could be interpreted as a behavioral response to stress introduced by DM. However, DM at a lethal concentration of 10 × MIC affected glucose decomposition by inhibiting mainly the HMP pathway in E. coli.

Evidence for the Hexose Monophosphate Pathway for Glucose Metabolism in Human Pancreatic β-Cells

Nature ◽  
1960 ◽  
Vol 185 (4711) ◽  
pp. 468-469 ◽  
Author(s):  
JAMES B. FIELD ◽  
PHYLLIS JOHNSON ◽  
BETTY HERRING ◽  
ARNOLD N. WEINBERG
Keyword(s):  
Glucose Metabolism ◽  
Hexose Monophosphate ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Hexose Monophosphate Pathway

The Control of Pyruvate Kinases of Escherichia coli. II. Effectors and Regulatory Properties of the Enzyme Activated by Ribose 5-Phosphate

1975 ◽  
Vol 53 (4) ◽  
pp. 444-454 ◽  
Author(s):  
E. Bruce Waygood ◽  
M. Khalil Rayman ◽  
B. D. Sanwal
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Active Form ◽  
Adenosine Diphosphate ◽  
Sucrose Density Gradient ◽  
Hexose Monophosphate ◽  
Dissociation Equilibrium ◽  
Hexose Monophosphate Pathway ◽  
Sugar Phosphates ◽  
Pyruvate Kinases

The pyruvate kinases of Escherichia coli activated by ribose 5-phosphate (RP) has been partially purified. The active form of the enzyme has a molecular weight of about 180 000 as judged by sucrose density gradient centrifugations and Sephadex G-150 chromatography. On dissociation in the absence of sulfhydryl reagents such as dithiothreitol, the enzyme is inactivated and it has a molecular weight of about 110 000. Various substrates and effectors of the enzyme, with the exception of phosphate, do not influence the association–dissociation equilibrium of the enzyme.The enzyme, unlike pyruvate kinases from many other sources, is not activated by potassium ions. Sulfate and phosphate ions are inhibitory to the enzyme. Phosphate seems to be an allosteric inhibitor and its effect is completely antagonized by activators. The enzyme is activated in an allosteric manner by two classes of compounds, nucleoside monophosphates and sugar phosphates of the hexose monophosphate pathway. Amongst the nucleotides, guanosine 5′-phosphate and adenosine 5′-phosphate are the most effective activators. Amongst the hexose monophosphate pathway intermediates, RP is the most powerful activator, with apparent activation constants as low as 1 μM. Sugar phosphates esterified at C-1 or both terminal positions are entirely ineffective in activation. The effectors act by changing the Michaelis constant for the substrates. Both of the substrates of the enzyme, adenosine diphosphate and phosphoenolpyruvate, yield cooperative rate–concentration plots in the presence of unsaturating concentrations of the fixed changing substrate. The initial velocity plots for both substrates become hyperbolic in the presence of saturating concentrations of RP.

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