Open AccessGlucose and the Metabolism of Adenosine 3′:5′-Cyclic Monophosphate in Escherichia coli
Author(s) -
Alan Peterkofsky,
Celia Gazdar
Publication year - 1971
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.68.11.2794
Subject(s) - escherichia coli , adenylate kinase , extracellular , phosphodiesterase , adenosine , biochemistry , metabolism , cyclase , tryptophanase , biology , enzyme , glucose transporter , cyclic adenosine monophosphate , chemistry , endocrinology , gene , receptor , insulin
Measurements of adenosine 3′:5′-cyclic monophosphate (cAMP) concentrations have been made inEscherichia coli under various conditions. Different strains ofE. coli accumulate different extracellular concentrations of cAMP (0.2-4 μm) at stationary phase. Mutation at the RNA control locus does not affect the accumulation pattern. Growth of the bacteria in minimalsalts medium leads to a greater accumulation of cAMP than growth in nutrient broth. Partition studies show that essentially all of the cAMP that is accumulated is found in the medium rather than in the cells. Kinetic studies show that most of the cAMP is formed coincidentally with exhaustion of glucose from the medium. Growth on high concentrations of glucose leads to inhibition of cAMP formation. Other carbon sources cannot substitute for glucose in this inhibitory effect. Measurements of enzyme activities indicate that glucose suppression of cAMP formation cannot be accounted for by a decreased activity of adenylate cyclase or an increased activity of cAMP phosphodiesterase (EC 3.1.3.7).