Limits...
A mathematical model for the adenylosuccinate synthetase reaction involved in purine biosynthesis.

Oshchepkova-Nedosekina EA, Likhoshvai VA - Theor Biol Med Model (2007)

Bottom Line: The advantage of our model is that it includes relationships between the reaction rate, the concentrations of three substrates (GTP, IMP and ASP), the effects of five inhibitors (GMP, GDP, AMP, ASUC and SUCC), and the influence of Mg2+ ions.The model was tested for adequacy using experimental data published elsewhere.The values obtained for the parameters are as follows: Vmax = 1.35.10-3 mM/min, KmGTP = 0.023 mM, KmIMP = 0.02 mM, KmASP = 0.3 mM, KiGMP = 0.024 mM, KiGDP = 8.10-3 mM, KiAMP = 0.01 mM, KiASUC = 7.5.10-3 mM, KiSUCC = 8 mM, KmMg = 0.08 mM.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia. nzhenia@bionet.nsc.ru

ABSTRACT

Background: Development of the mathematical models that adequately describe biochemical reactions and molecular-genetic mechanisms is one of the most important tasks in modern bioinformatics. Because the enzyme adenylosuccinate synthetase (AdSS) has long been extensively studied, a wealth of kinetic data has been accumulated.

Results: We describe a mathematical model for the reaction catalyzed by AdSS. The model's parameters were fitted to experimental data obtained from published literature. The advantage of our model is that it includes relationships between the reaction rate, the concentrations of three substrates (GTP, IMP and ASP), the effects of five inhibitors (GMP, GDP, AMP, ASUC and SUCC), and the influence of Mg2+ ions.

Conclusion: Our model describes the reaction catalyzed by AdSS as a fully random process. The model structure implies that each of the inhibitors included in it is only competitive to one of the substrates. The model was tested for adequacy using experimental data published elsewhere. The values obtained for the parameters are as follows: Vmax = 1.35.10-3 mM/min, KmGTP = 0.023 mM, KmIMP = 0.02 mM, KmASP = 0.3 mM, KiGMP = 0.024 mM, KiGDP = 8.10-3 mM, KiAMP = 0.01 mM, KiASUC = 7.5.10-3 mM, KiSUCC = 8 mM, KmMg = 0.08 mM.

Show MeSH

Related in: MedlinePlus

Relationships between the reaction rate and concentration of ASP under different conditions. Experimental data from [6].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1808444&req=5

Figure 5: Relationships between the reaction rate and concentration of ASP under different conditions. Experimental data from [6].

Mentions: Also, our model treats AMP as a competitive inhibitor of IMP [6]. From the work of Wyngaarden and Greenland [6], we calculated the constants of the GMP and AMP effects (Fig. 5, lines 1 and 2): KiGMP = 0.024 mM, KiAMP = 0.01 mM. However, these estimates may suffer from a lack of consistency within the experimental data.


A mathematical model for the adenylosuccinate synthetase reaction involved in purine biosynthesis.

Oshchepkova-Nedosekina EA, Likhoshvai VA - Theor Biol Med Model (2007)

Relationships between the reaction rate and concentration of ASP under different conditions. Experimental data from [6].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1808444&req=5

Figure 5: Relationships between the reaction rate and concentration of ASP under different conditions. Experimental data from [6].
Mentions: Also, our model treats AMP as a competitive inhibitor of IMP [6]. From the work of Wyngaarden and Greenland [6], we calculated the constants of the GMP and AMP effects (Fig. 5, lines 1 and 2): KiGMP = 0.024 mM, KiAMP = 0.01 mM. However, these estimates may suffer from a lack of consistency within the experimental data.

Bottom Line: The advantage of our model is that it includes relationships between the reaction rate, the concentrations of three substrates (GTP, IMP and ASP), the effects of five inhibitors (GMP, GDP, AMP, ASUC and SUCC), and the influence of Mg2+ ions.The model was tested for adequacy using experimental data published elsewhere.The values obtained for the parameters are as follows: Vmax = 1.35.10-3 mM/min, KmGTP = 0.023 mM, KmIMP = 0.02 mM, KmASP = 0.3 mM, KiGMP = 0.024 mM, KiGDP = 8.10-3 mM, KiAMP = 0.01 mM, KiASUC = 7.5.10-3 mM, KiSUCC = 8 mM, KmMg = 0.08 mM.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia. nzhenia@bionet.nsc.ru

ABSTRACT

Background: Development of the mathematical models that adequately describe biochemical reactions and molecular-genetic mechanisms is one of the most important tasks in modern bioinformatics. Because the enzyme adenylosuccinate synthetase (AdSS) has long been extensively studied, a wealth of kinetic data has been accumulated.

Results: We describe a mathematical model for the reaction catalyzed by AdSS. The model's parameters were fitted to experimental data obtained from published literature. The advantage of our model is that it includes relationships between the reaction rate, the concentrations of three substrates (GTP, IMP and ASP), the effects of five inhibitors (GMP, GDP, AMP, ASUC and SUCC), and the influence of Mg2+ ions.

Conclusion: Our model describes the reaction catalyzed by AdSS as a fully random process. The model structure implies that each of the inhibitors included in it is only competitive to one of the substrates. The model was tested for adequacy using experimental data published elsewhere. The values obtained for the parameters are as follows: Vmax = 1.35.10-3 mM/min, KmGTP = 0.023 mM, KmIMP = 0.02 mM, KmASP = 0.3 mM, KiGMP = 0.024 mM, KiGDP = 8.10-3 mM, KiAMP = 0.01 mM, KiASUC = 7.5.10-3 mM, KiSUCC = 8 mM, KmMg = 0.08 mM.

Show MeSH
Related in: MedlinePlus