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Mammalian Cell Physiology
Published in Anthony S. Lubiniecki, Large-Scale Mammalian Cell Culture Technology, 2018
The activities of key enzymes in the pentose phosphate pathway were also found to be elevated in tumor as compared to normal liver tissue but were generally not linked to growth rate. However, the activity of phosphoribosylpyrophosphate (PRPP) synthetase was found to be positively correlated with the tumor growth rate. PRPP can be used in both salvage and de novo pathways of purine and pyrimidine biosynthesis, functioning as an allosteric activator of the rate-limiting enzyme of de novo pyrimidine biosynthesis. Activation of these enzymes would therefore greatly favor DNA replication and growth. Activities of enzymes involved in pentose phosphate synthesis and utilization are compared in transformed and normal tissues from both liver and kidney in Table 3. Weber (84, 85) concluded that an imbalance in the carbohydrate metabolism of cancer cells is the result of reprogramming of gene expression. He suggests that the expression of key enzymes will alter the phenotype of cancer cells, giving them a growth advantage over normal tissue.
Growth and genetic analysis of Pseudomonas BT1 in a high-thiourea environment reveals the mechanisms by which it restores the ability to remove ammonia nitrogen from wastewater
Published in Environmental Technology, 2022
Jingxuan Deng, Zhenxing Huang, Wenquan Ruan
The C, N, and S metabolic processes of BT1 were constructed based on gene annotation. In terms of C metabolism, BT1 has the complete starch and sucrose metabolism, pentose phosphate pathway, glycolysis/gluconeogenesis, and citrate cycle (TCA cycle). It can convert cellodextrin, cellobiose, and maltose into glucose or directly use glucose as the initial C source and then metabolise glucose into alpha-D-glucose-1P through the process of starch and sucrose metabolism. Alpha-D-glucose-1P enters the pentose phosphate pathway and is metabolised into pyruvate and PRPP, which can be further metabolised into energy, amino acids, purine, and pyrimidine metabolism. In addition, BT1 has a completed tricarboxylic acid (TCA) cycle, and it can convert oxaloacetate metabolised by the TCA cycle into pyruvate through glycolysis and gluconeogenesis (Figure 2).