Open AccessEvidence for a pentose phosphate pathway in Helicobacter pylori
Author(s) -
Mendz George L.,
Hazell Stuart L.
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04619.x
Subject(s) - transaldolase , pentose phosphate pathway , transketolase , dihydroxyacetone phosphate , biochemistry , triosephosphate isomerase , dehydrogenase , enzyme , isomerase , pentose , ribose , chemistry , phosphogluconate dehydrogenase , biology , glucose 6 phosphate dehydrogenase , glycolysis , fermentation
Evidence for the presence of enzymes of the pentose phosphate pathway in Helicobacter pylori was obtained using 31 P nuclear magnetic resonance spectroscopy. Activities of enzymes which are part of the oxidative and non‐oxidative phases of the pathway were observed directly in incubations of bacterial lysates with pathway intermediates. Generation of NADPH and 6‐phosphogluconate from NADP + and glucose 6‐phosphate indicated the presence of glucose 6‐phosphate dehydrogenase and 6‐phosphogluconolactonase. Reduction of NADP + with production of ribulose 5‐phosphate from 6‐phosphogluconate revealed 6‐phosphogluconate dehydrogenase activity. Phosphopentose isomerase and transketolase activities were observed in incubations containing ribulose 5‐phosphate and xylulose 5‐phosphate, respectively. The formation of erythrose 4‐phosphate from xylulose 5‐phosphate and ribose 5‐phosphate suggested the presence of transaldolase. The activities of this enzyme and triosephosphate isomerase were observed directly in incubations of bacterial lysates with dihydroxyacetone phosphate and sedoheptulose 7‐phosphate. Glucose‐6‐phosphate isomerase activity was measured in incubations with fructos 6‐phosphate. The presence of these enzymes in H. pylori suggested the existence of a pentose phosphate pathway in the bacterium, possibly as a mechanism to provide NADPH for reductive biosynthesis and ribose 5‐phosphate for synthesis of nucleic acids.