TY - JOUR
T1 - Monte-Carlo modeling of the central carbon metabolism of Lactococcus lactis
T2 - Insights into metabolic regulation.
AU - Murabito, Ettore
AU - Verma, Malkhey
AU - Bekker, Martijn
AU - Bellomo, Domenico
AU - Westerhoff, Hans V.
AU - Teusink, Bas
AU - Steuer, Ralf
N1 - BB/C008219/1, Biotechnology and Biological Sciences Research Council, United KingdomBB/F003528/1, Biotechnology and Biological Sciences Research Council, United KingdomBB/F003544/1, Biotechnology and Biological Sciences Research Council, United KingdomBB/I004696/1, Biotechnology and Biological Sciences Research Council, United KingdomBB/I00470X/1, Biotechnology and Biological Sciences Research Council, United KingdomBB/I017186/1, Biotechnology and Biological Sciences Research Council, United KingdomEP/D508053/1, Biotechnology and Biological Sciences Research Council, United Kingdom
PY - 2014/9/30
Y1 - 2014/9/30
N2 - Metabolic pathways are complex dynamic systems whose response to perturbations and environmental challenges are governed by multiple interdependencies between enzyme properties, reactions rates, and substrate levels. Understanding the dynamics arising from such a network can be greatly enhanced by the construction of a computational model that embodies the properties of the respective system. Such models aim to incorporate mechanistic details of cellular interactions to mimic the temporal behavior of the biochemical reaction system and usually require substantial knowledge of kinetic parameters to allow meaningful conclusions. Several approaches have been suggested to overcome the severe data requirements of kinetic modeling, including the use of approximative kinetics and Monte-Carlo sampling of reaction parameters. In this work, we employ a probabilistic approach to study the response of a complex metabolic system, the central metabolism of the lactic acid bacterium Lactococcus lactis, subject to perturbations and brief periods of starvation. Supplementing existing methodologies, we show that it is possible to acquire a detailed understanding of the control properties of a corresponding metabolic pathway model that is directly based on experimental observations. In particular, we delineate the role of enzymatic regulation to maintain metabolic stability and metabolic recovery after periods of starvation. It is shown that the feedforward activation of the pyruvate kinase by fructose-1,6-bisphosphate qualitatively alters the bifurcation structure of the corresponding pathway model, indicating a crucial role of enzymatic regulation to prevent metabolic collapse for low external concentrations of glucose. We argue that similar probabilistic methodologies will help our understanding of dynamic properties of small-, medium- and large-scale metabolic networks models.
AB - Metabolic pathways are complex dynamic systems whose response to perturbations and environmental challenges are governed by multiple interdependencies between enzyme properties, reactions rates, and substrate levels. Understanding the dynamics arising from such a network can be greatly enhanced by the construction of a computational model that embodies the properties of the respective system. Such models aim to incorporate mechanistic details of cellular interactions to mimic the temporal behavior of the biochemical reaction system and usually require substantial knowledge of kinetic parameters to allow meaningful conclusions. Several approaches have been suggested to overcome the severe data requirements of kinetic modeling, including the use of approximative kinetics and Monte-Carlo sampling of reaction parameters. In this work, we employ a probabilistic approach to study the response of a complex metabolic system, the central metabolism of the lactic acid bacterium Lactococcus lactis, subject to perturbations and brief periods of starvation. Supplementing existing methodologies, we show that it is possible to acquire a detailed understanding of the control properties of a corresponding metabolic pathway model that is directly based on experimental observations. In particular, we delineate the role of enzymatic regulation to maintain metabolic stability and metabolic recovery after periods of starvation. It is shown that the feedforward activation of the pyruvate kinase by fructose-1,6-bisphosphate qualitatively alters the bifurcation structure of the corresponding pathway model, indicating a crucial role of enzymatic regulation to prevent metabolic collapse for low external concentrations of glucose. We argue that similar probabilistic methodologies will help our understanding of dynamic properties of small-, medium- and large-scale metabolic networks models.
U2 - 10.1371/journal.pone.0106453
DO - 10.1371/journal.pone.0106453
M3 - Article
C2 - 25268481
VL - 9
JO - PLoS ONE
JF - PLoS ONE
IS - 9
M1 - e106453
ER -