Also, note that our model can be easily modified to investigate scenarios where one or more pathways are not active due to the absence of expression of the pathway enzymes, by simply setting to zero the corresponding pathway rate.
When making an estimate of the contribution of each pathway to the crowding of the cell cytoplasm we make use of the total sum of the enzyme masses that are necessary to maintain the pathway rate.
Our study, along with other recent work [25], shows that intra-line variation in pathway rates can cause significant variation in cell fate in response to drug, which presumably contributes to the difficulty of completely eradicating cancer using drug treatments.
In these equations the product by the mass and the division by the cell volume takes into account that the rates r are commonly reported in the literature per unit of dry weight, while the pathway rates f are reported per unit of cell volume.
The similarities and differences between the metabolisms of these cell types are further investigated using a larger scale model, accounting for the need of biosynthetic precursors in proliferating cells and amino acids catabolism. Figure 1 depicts a schematic model of energy metabolism, including glucose- and fatty acid catabolism with pathway rates fG and fFA, respectively.
Adverse event management is different between countries, in terms of choice of drugs, basic treatment pathway, rates of consultations, etc.
9, 18 The overexpression of genes encoding various isoforms of the cytokinin pathway rate-limiting enzyme IPT can enhance the levels of plant cytokinins.
Finally, KEGG analysis indicated increased expression in the PNT of six genes mediating steroid biogenesis, which are essentially members of the HMG-CoA reductase/mevalonate pathway (including HMGCR, the mevalonate pathway rate-limiting enzyme) that leads to cholesterol (and ergosterol) production (Table 2; supplementary material Table S3; Fig. 4C).
Alternatively, glucose that has specific carbon atoms labelled with radioactive (C, C, H) or stable (C) isotopes is used to evaluate pathway rates and oxidative metabolism by means of label release in by-products (lactate, CO2 or H2O) or trapping of label in the large unlabelled amino acid pools derived from the TCA cycle.
Specific reaction pathways and rate constants which affect the computation of these observations are discussed.
