Metabolic flux analysis for human therapeutic protein productions and hypothesis for new therapeutical strategies in medicine

This work may be considered as a model study for therapeutic protein production, and a theoretical approach to hypothesise new medical strategies to further applied medical questions. A comprehensive generalised metabolic reaction network of Bacillus licheniformis that considers 149 reaction fluxes and 106 metabolites was used in the mass flux balance-based stoichiometric model for the analysis of human leukocyte interferon (IFN-alpha(1)) and erythropoietin (EPO) production capacities of recombinant Bacillus species. The importance of cellular energetics on optimum performance was quantitatively assessed. The metabolic pathways leading to optimised IFN-alpha(1) and EPO overproduction were determined for the two carbon sources that have different reduction degrees (gamma), i.e. glucose (gamma=4.0) and citrate (gamma=3.0), and the variation of the fluxes were obtained. Metabolic capacity analyses showed that maximum IFN-alpha(1) and EPO synthesis rates were, respectively, 0.062 and 0.055 mmol g(-1) DWh(-1) at mu=0h(-1) when glucose uptake rate was 10 mmol g(-1) DWh(-1); and IFN-alpha(1) and EPO synthesis rates decreased, respectively, 1.70- and 1.75-fold when citrate was used as the carbon source. The flux distributions showed that the amino acid composition of the proteins influence the production. Leucine appears to be the most important amino acid for both IFN-alpha(1) and EPO production. Consequently, pyruvate seems to be the critical main branch point and B. pasteurii seems to be the favourable host for therapeutical protein production due to the high leucine uptake capacity. The results encourage the discussion on the potential strategies for improving production of IFN-alpha(1) and EPO, and further enable us to assert medical hypothesis in order to support the immune system of the human body against the deficiencies of the synthesis of IFN-alpha(1) and EPO in the human cells.


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In this study, the performance of a two stage rotating biological contactor (RBC) was evaluated for the treatment of synthetic wastewater containing peptone, 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) at 5 rpm. Also, the effect of biogenic substrate (peptone) concentration on the reactor performance was investigated. High chlorophenols (> 98%) and COD (> 94%) removals were achieved throughout the reactor operation in the first stage and the second stage behaved as a polishing step. The observed ...
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The various domains of a plant disease resistance protein from wheat were found to be interacting with yeast proteins when screened via yeast two hybrid analyses. These genes are considered to play roles in disease resistance response. Thus, the expression levels in Mla3 mediated Powdery Mildew (Blumeria graminis f.sp. hordei, Bgh) disease resistance in barley were determined. The barley homologs of ARD1, CPR7, CSE1, GCN2 and SRP72, were partially cloned and sequenced. Their differential expression was conf...
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The aim of this work was to develop an effective fed-batch feeding strategy to enhance recombinant glucose isomerase (r-GI) production by recombinant Escherichia coli BL21 (DE3) pLysS on an industrially relevant feedstock without the application of an exogenous inducer. Following the batch operation (0 < t < 7H), the effects of pulse and/or continuous feeding of hydrolyzed beet molasses were investigated under five different feeding strategies. The two most promising strategies with respect to r-GI activity...
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Effects of medium components on intracellular glucose isomerase (GI) production were investigated by Bacillus thermoantarcticus. The highest GI activity was obtained as 1630 U dm(-3) in the medium containing (g dm(-3)): 10.6, birchwood-xylan: 5.6, yeast extract: 5.9 (NH(4))(2)SO(4) at T = 55 C in 33 cm(-3) shake-flasks. When birchwood-xylan was replaced with oat spelt- or beechwood-xylan, GI activity decreased to 1372 and 1308 U dm(-3). respectively. Effects of pH at uncontrolled-pH (pH(UC) = 6.0) and contr...
Citation Formats
P. Çalık, “Metabolic flux analysis for human therapeutic protein productions and hypothesis for new therapeutical strategies in medicine,” BIOCHEMICAL ENGINEERING JOURNAL, pp. 49–68, 2002, Accessed: 00, 2020. [Online]. Available: