4-fold with a V diff confidence score of >0.7, while phosphoglycerate mutase and triosephosphate isomerase increased by ~1.4-fold, but only with a V diff confidence score of >0.2. While Raman et al.
(2011) observed a decrease in mRNA expression of ATP-dependent phosphofuctokinase Cthe_1261 and PPi-dependent phosphofructokinase Cthe_0389 during transition to stationary phase, we did not observe any changes in protein levels. However, we did observe a decrease in phosphoglycerate mutase Cthe_0946 and an increase in Cthe_1292, consistent with cellulose grown C. thermocellum mRNA profiles . Energy storage Glycogen, an energy and Idasanutlin supplier carbon storage compound, is commonly synthesized during periods of slow or no growth, especially in carbon excess, and is often associated with sporulation [71, 72]. Glucose-1-P adenylyltransferase (Cthe_3166 and Cthe_3167), involved in the synthesis of the primary glucosyl donor ADP-glucose, was detected in exponential phase cell-free extracts using shotgun 2D-HPLC-MS/MS (Figure 2b, Additional file 4). Of the two genes encoding glycogen synthase (Cthe_1284 and Cthe_0282), which catalyzes α-1,4-glucosyl linkages to a pre-existing α-1,4-glucan, levels of Cthe_1284 were ~15-fold higher than that of Cthe_0282, suggesting SAHA concentration it is the primary glycogen synthase in C. thermocellum. While the
level of 1,4-α-glucan branching enzyme, www.selleckchem.com/products/ink128.html required for catalyzing α-1,6-glucosyl linkages, was below our threshold cutoff in shotgun analysis, it was detected in 4-plex analysis. A putative 1,4-α-glycogen debranching enzyme and α-glucan phosphorylase, required for glycogen breakdown, was also detected in exponential phase cultures. On the basis of simultaneous glucose-1-P
adenylyltransferase, glycogen synthase, and glycogen phosphorylase activities in C. cellulolyticum cell-free extracts, Guedon et al. have proposed that glycogen synthesis and glycogenolysis can occur simultaneously . While allosteric regulation of these enzymes has been demonstrated in E. coli, the effect of allosteric regulators on these enzymes was not studied in C. cellulolyticum. Alternatively, Protirelin the simultaneous detection of enzymes involved in glycogen synthesis as well as glycogen breakdown may be a consequence of metabolic heterogeneity within the culture, where some cells are expressing pathways for glycogen synthesis while others are expression pathways capable of glycogenolysis. While this type of cell-to-cell variation has been observed in Bacillus subtilis, it cannot be verified using proteomics as these variations are homogenized as one examines bulk mixtures of cells. We observed a 3.5-fold increase in glycogen synthase Cthe_0282 and a 2.5-fold increase in 1,4-α-branching enzyme in stationary phase, suggesting that glycogen synthesis is favoured during stationary phase.