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Mechanism for regulating the distribution of glucose carbon between the Embden-Meyerhof and hexose-monophosphate pathways in Streptococcus faecalis.
J Bacteriol. 1971 May; 106(2):456-67.JB

Abstract

Glucose-adapted Streptococcus faecalis produced little if any (14)CO(2) from glucose-1-(14)C, although high levels of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) were detected in cell-free extracts. Metabolism of glucose through the oxidative portion of the hexose-monophosphate pathway was shown to be regulated in this organism by the specific inhibitory interaction of the Embden-Meyerhof intermediate, fructose-1, 6-diphosphate (FDP), with 6-phosphogluconate dehydrogenase. Glucose-6-phosphate dehydrogenase activity was unaffected by FDP. The S. faecalis 6-phosphogluconate dehydrogenase was partially purified from crude extracts by standard fractionation procedures and certain kinetic parameters of the FDP-mediated inhibition were investigated. The negative effector was shown to cause a decrease in V(max) and an increase in the apparent K(m) for both 6-phosphogluconate and nicotinamide adenine dinucleotide phosphate (NADP). These effects were apparently a consequence of the ligand interacting with the enzyme at a site distinct from either the substrate or the coenzyme sites. Among the evidence supporting this was the fact that beta-mercaptoethanol blocked completely FDP inhibition, but had no effect on catalytic activity. The possibility that the regulation of 6-phosphogluconate dehydrogenase activity by FDP might be of some general significance was suggested by the observation that this enzyme from several other sources was also sensitive to FDP.

Authors

No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

4396792

Citation

Brown, A T., and C L. Wittenberger. "Mechanism for Regulating the Distribution of Glucose Carbon Between the Embden-Meyerhof and Hexose-monophosphate Pathways in Streptococcus Faecalis." Journal of Bacteriology, vol. 106, no. 2, 1971, pp. 456-67.
Brown AT, Wittenberger CL. Mechanism for regulating the distribution of glucose carbon between the Embden-Meyerhof and hexose-monophosphate pathways in Streptococcus faecalis. J Bacteriol. 1971;106(2):456-67.
Brown, A. T., & Wittenberger, C. L. (1971). Mechanism for regulating the distribution of glucose carbon between the Embden-Meyerhof and hexose-monophosphate pathways in Streptococcus faecalis. Journal of Bacteriology, 106(2), 456-67.
Brown AT, Wittenberger CL. Mechanism for Regulating the Distribution of Glucose Carbon Between the Embden-Meyerhof and Hexose-monophosphate Pathways in Streptococcus Faecalis. J Bacteriol. 1971;106(2):456-67. PubMed PMID: 4396792.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Mechanism for regulating the distribution of glucose carbon between the Embden-Meyerhof and hexose-monophosphate pathways in Streptococcus faecalis. AU - Brown,A T, AU - Wittenberger,C L, PY - 1971/5/1/pubmed PY - 1971/5/1/medline PY - 1971/5/1/entrez SP - 456 EP - 67 JF - Journal of bacteriology JO - J. Bacteriol. VL - 106 IS - 2 N2 - Glucose-adapted Streptococcus faecalis produced little if any (14)CO(2) from glucose-1-(14)C, although high levels of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) were detected in cell-free extracts. Metabolism of glucose through the oxidative portion of the hexose-monophosphate pathway was shown to be regulated in this organism by the specific inhibitory interaction of the Embden-Meyerhof intermediate, fructose-1, 6-diphosphate (FDP), with 6-phosphogluconate dehydrogenase. Glucose-6-phosphate dehydrogenase activity was unaffected by FDP. The S. faecalis 6-phosphogluconate dehydrogenase was partially purified from crude extracts by standard fractionation procedures and certain kinetic parameters of the FDP-mediated inhibition were investigated. The negative effector was shown to cause a decrease in V(max) and an increase in the apparent K(m) for both 6-phosphogluconate and nicotinamide adenine dinucleotide phosphate (NADP). These effects were apparently a consequence of the ligand interacting with the enzyme at a site distinct from either the substrate or the coenzyme sites. Among the evidence supporting this was the fact that beta-mercaptoethanol blocked completely FDP inhibition, but had no effect on catalytic activity. The possibility that the regulation of 6-phosphogluconate dehydrogenase activity by FDP might be of some general significance was suggested by the observation that this enzyme from several other sources was also sensitive to FDP. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/4396792/Mechanism_for_regulating_the_distribution_of_glucose_carbon_between_the_Embden_Meyerhof_and_hexose_monophosphate_pathways_in_Streptococcus_faecalis_ L2 - http://jb.asm.org/cgi/pmidlookup?view=long&pmid=4396792 DB - PRIME DP - Unbound Medicine ER -