Muscle Purine Nucleotide Cycle Enzymes in Exercise Intolerance

1998 ◽  
pp. 205-209 ◽  
Author(s):  
Maria-Grazia Operti ◽  
M.-Françoise Vincent ◽  
Jean-Marie Brucher ◽  
Georges Van den Berghe
Keyword(s):  
Exercise Intolerance ◽  
Purine Nucleotide ◽  
Purine Nucleotide Cycle

Enzymes of the purine nucleotide cycle in muscle of patients with exercise intolerance

1998 ◽  
Vol 21 (3) ◽  
pp. 401-403 ◽  
Author(s):  
Maria-Grazia Operti ◽  
M.-Françoise Vincent ◽  
Jean-Marie Brucher ◽  
Georges van den Berghe
Keyword(s):  
Exercise Intolerance ◽  
Purine Nucleotide ◽  
Purine Nucleotide Cycle

Muscle purine nucleotide cycle enzymes in exercise intolerance

1997 ◽  
Vol 30 (3) ◽  
pp. 288
Author(s):  
M.G. Operti ◽  
M.F. Vincent ◽  
J.M. Brucher ◽  
G. Van den Berghe
Keyword(s):  
Exercise Intolerance ◽  
Purine Nucleotide ◽  
Purine Nucleotide Cycle

scholarly journals The Purine Nucleotide Cycle

1972 ◽  
Vol 247 (1) ◽  
pp. 162-169 ◽  
Author(s):  
Keith Tornheim ◽  
John M. Lowenstein
Keyword(s):  
Purine Nucleotide ◽  
Purine Nucleotide Cycle

scholarly journals The role of glutamine oxidation and the purine nucleotide cycle for adaptation of tumour energetics to the transition from the anaerobic to the aerobic state

1988 ◽  
Vol 252 (2) ◽  
pp. 381-386 ◽  
Author(s):  
Z Kovacević ◽  
D Jerance ◽  
O Brkljac
Keyword(s):  
Adenine Nucleotide ◽  
The Other ◽  
Purine Nucleotide ◽  
Purine Nucleotide Cycle ◽  
Adenine Nucleotide Pool

It is proposed that the purine nucleotide cycle and glutamine oxidation play a key role in the adaptation of tumour energetics to the transition from the anaerobic to the aerobic state. In support of this proposal, it was found that glutamine and inosine markedly increase total adenylates in the presence of oxygen, whereas the addition of hadacidin abolishes this effect. Transition of the cells from the anaerobic to the aerobic state, and vice versa, in the presence of glutamine plus inosine revealed that there are two components of the adenine nucleotide pool, one which is stable and the other which is variable and responds to the aerobic-anaerobic transition. This part of the pool undergoes degradation or resynthesis owing to activation of the enzymes of the purine nucleotide cycle. Resynthesis of the pool is accompanied by substantial net utilization of aspartate, which is produced by glutamine oxidation. This is supported by the experiments in which the cells were alternately incubated with nitrogen or oxygen, demonstrating that hadacidin significantly decreased utilization of aspartate and regeneration of ATP owing to inhibition of adenylosuccinate synthase.

Binding of adenylosuccinate synthetase to contractile proteins of muscle

1989 ◽  
Vol 257 (1) ◽  
pp. C29-C35 ◽  
Author(s):  
J. P. Manfredi ◽  
R. Marquetant ◽  
A. D. Magid ◽  
E. W. Holmes
Keyword(s):  
Ionic Strength ◽  
Dissociation Constant ◽  
Thin Filament ◽  
Contractile Proteins ◽  
Purine Nucleotide ◽  
Apparent Dissociation Constant ◽  
Thin Filaments ◽  
Adenylosuccinate Synthetase ◽  
Purine Nucleotide Cycle ◽  
Low Ionic Strength

The muscle isozyme of adenylosuccinate synthetase (AdSS), an enzyme of the purine nucleotide cycle, has previously been shown to bind to purified F-actin in buffers of low ionic strength and pH (Ogawa et al. Eur. J. Biochem. 85: 331-338, 1978). We have extended these observations by measuring the association of both crude and purified AdSS with the contractile proteins of muscle in buffers of physiological ionic strength and pH. Under these conditions, the enzyme binds to F-actin, actin-tropomyosin complexes, reconstructed thin filaments, and myofibrils but not to myosin. The apparent dissociation constant of 1.2 microM and binding maximum of 2.6 nmol enzyme/mg myofibrils indicate that binding of AdSS to myofibrils can be physiologically significant. The results suggest that AdSS in muscle may be associated with the thin filament of myofibrils.

scholarly journals Characteristics of aspartate deamination by the puring nucleotide cycle in the cytosol fraction of rat liver

1975 ◽  
Vol 150 (2) ◽  
pp. 275-283 ◽  
Author(s):  
K M Moss ◽  
J D McGivan
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Nucleoside Triphosphate ◽  
Amp Deaminase ◽  
Purine Nucleotide ◽  
Major Pathway ◽  
Cytosol Fraction ◽  
Purine Nucleotide Cycle

1. The component reactions of the puring nucleotide cycle were studied in cytosol extracts of rat liver. 2. AMP deaminase was strongly activated by ATP and analogues of ATP. 3. IMP was converted into ATP by a system requiring the presence of aspartate, GTP and a nucleoside triphosphate-regenerating system. 4. Under appropriate conditions, NH3 was produced from aspartate. 5. From the rates at which these reactions occur it is concluded that the purine nucleotide cycle may have sufficient activity to be a major pathway of amino acid deamination in liver.

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