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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
35
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pubmed:dateCreated |
1991-1-23
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pubmed:abstractText |
Oscillatory behavior of glycolysis in cell-free extracts of rat skeletal muscle involves bursts of phosphofructokinase activity, due to autocatalytic activation by fructose-1,6-P2. Glucose-1,6-P2 similarly might activate phosphofructokinase in an autocatalytic manner, because it is produced in a side reaction of phosphofructokinase and in a side reaction of phosphoglucomutase using fructose-1,6-P2. When muscle extracts were provided with 1 mM ATP and 10 mM glucose, glucose-1,6-P2 accumulated in a stepwise, but monotonic, manner to 0.7 microM in 1 h. The stepwise increases occurred during the phases when fructose-1,6-P2 was available, consistent with glucose-1,6-P2 synthesis in the phosphoglucomutase side reaction. Addition of 5-20 microM glucose-1,6-P2 increased the frequency of the oscillations in a dose-dependent manner and progressively shortened the time interval before the first burst of phosphofructokinase activity. Addition of 30 microM glucose-1,6-P2 blocked the oscillations. The peak values of the [ATP]/[ADP] ratio were then eliminated, and the average [ATP]/[ADP] ratio was reduced by half. In the presence of higher, near physiological concentrations of ATP and citrate (which reduce the activation of phosphofructokinase by glucose-1,6-P2), high physiological concentrations of glucose-1,6-P2 (50-100 microM) increased the frequency of the oscillations and did not block them. We conclude that autocatalytic activation of phosphofructokinase by fructose-1,6-P2, but not by glucose-1,6-P2, is the mechanism generating the oscillations in muscle extracts. Glucose-1,6-P2 may nevertheless play a role in facilitating the initiation of the oscillations and in modulating their frequency.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adenine Nucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Citrates,
http://linkedlifedata.com/resource/pubmed/chemical/Fructosediphosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Glucose-6-Phosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Glucosephosphates,
http://linkedlifedata.com/resource/pubmed/chemical/NAD,
http://linkedlifedata.com/resource/pubmed/chemical/fructose-1,6-diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/glucose-1,6-bisphosphate
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
265
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
21441-7
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2254306-Adenine Nucleotides,
pubmed-meshheading:2254306-Animals,
pubmed-meshheading:2254306-Cell-Free System,
pubmed-meshheading:2254306-Citrates,
pubmed-meshheading:2254306-Fructosediphosphates,
pubmed-meshheading:2254306-Glucose-6-Phosphate,
pubmed-meshheading:2254306-Glucosephosphates,
pubmed-meshheading:2254306-Glycolysis,
pubmed-meshheading:2254306-Muscles,
pubmed-meshheading:2254306-NAD,
pubmed-meshheading:2254306-Periodicity,
pubmed-meshheading:2254306-Rats
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pubmed:year |
1990
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pubmed:articleTitle |
Oscillatory synthesis of glucose 1,6-bisphosphate and frequency modulation of glycolytic oscillations in skeletal muscle extracts.
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pubmed:affiliation |
Department of Biochemistry, Boston University School of Medicine, Massachusetts 02118.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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