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Glucose phosphorylation in Helicobacter pylori
1School of Biochemistry and Molecular Genetics, University of New South Wales, Kensington, Australia.
Archives of Biochemistry and Biophysics
|January 1, 1993
Summary
Helicobacter pylori phosphorylates only D-glucose, indicating specific glucokinase activity. This enzyme is primarily located in the bacterial cell envelope, suggesting its role in nutrient uptake.
Area of Science:
- Microbiology
- Biochemistry
Background:
- Helicobacter pylori is a significant human pathogen.
- Understanding its metabolic pathways is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate saccharide kinase activities in Helicobacter pylori.
- To identify specific sugar phosphorylation capabilities and enzyme localization.
Main Methods:
- Bacterial lysates incubated with ATP and various mono-/disaccharides.
- Phosphorylated products monitored using 13C or 31P nuclear magnetic resonance (NMR) spectroscopy.
- Kinase activity quantified by measuring glucose 6-phosphate formation rates.
Main Results:
- D-Glucose was the sole sugar phosphorylated among all tested carbohydrates.
- Enzyme kinetics (high KM, no substrate inhibition) suggest glucokinase activity, not general hexokinase.
- Most glucose kinase activity localized to the pellet fraction, indicating cell envelope association.
Conclusions:
- Helicobacter pylori possesses a specific glucokinase, not a broad-spectrum hexokinase.
- The enzyme is likely associated with the bacterial cell envelope, potentially involved in glucose transport and metabolism.