Enzymic flux rates within the mononucleotides of the mouse liver
| Autor: | D. Zahn, Horst Frunder, Reinhard Klinger |
|---|---|
| Rok vydání: | 1969 |
| Předmět: |
GTP'
Uracil Nucleotides Kinetics Oxidative phosphorylation Cytosine Nucleotides Biochemistry Models Biological Oxidative Phosphorylation Phosphates Substrate-level phosphorylation Mice Adenosine Triphosphate Animals chemistry.chemical_classification Nucleoside-phosphate kinase Adenine Nucleotides Nucleotides Phosphotransferases Phosphorus Isotopes Nucleoside-diphosphate kinase Guanine Nucleotides Enzyme chemistry Liver Flux (metabolism) Mathematics |
| Zdroj: | European journal of biochemistry. 11(3) |
| ISSN: | 0014-2956 |
| Popis: | Within the first 30 sec after intravenous injection of [32P]Pi the P-flux was measured within the mononucleotide pool of the normal mouse liver. It is only in this short time interval that the dynamic phase of tracer kinetics is met, permitting proper calculations of flux rates of the mononucleotides with high turnover. The simplified model applied for the calculation of the stated flux rates describes fairly adequately the main pathways within the complex network of possible mononucleotide interconversions. The P-flux from the β-P of ADP to the β-P of ATP, catalyzed preferentially by oxidative and substrate phosphorylation amounts to 33 μmoles per g fresh liver per min. 12, 0.7, 0.3 and 0.01 μmoles γ-P of ATP are transfered per g per min to the β-P of ADP, UDP, GDP and CDP, respectively, via the group nucleoside monophosphate kinases. These flux rates are 1–2 orders of magnitude less than expected from the kinetics behaviour of the involved enzymes in vitro. The reverse reaction of the nucleoside monophosphate kinases is probably small. 9, 4 and 0.5 μmoles of the γ-P of ATP are transferred per g per min to the γ-P of GTP, UTP and CTP via nucleoside diphosphate kinase. |
| Databáze: | OpenAIRE |
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