PomBioTech GmbH

Saarbrücken, Germany

PomBioTech GmbH

Saarbrücken, Germany
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Parr M.K.,Free University of Berlin | Parr M.K.,German Sport University Cologne | Zollner A.,PomBioTech GmbH | Zollner A.,Dunn Labortechnik GmbH | And 6 more authors.
Toxicology Letters | Year: 2012

The metabolism of a variety of anabolic steroids frequently misused for doping purposes has been investigated in the last years. This research mainly focused on main and long-term metabolites suitable for detection, but detailed clearance mechanisms have rarely been elucidated. Recent studies on metandienone focused on the identification of 17β-hydroxymethyl-17α-methyl-18-norandrosta-1,4,13-trien-3-one (20βOH-NorMD) as long-term metabolite, however, the metabolic pathway of its generation remained unclear.Metandienone and its Wagner-Meerwein rearrangement product 17,17-dimethyl-18-norandrosta-1,4,13-trien-3-one (NorMD) were hydroxylated by different human cytochrome P450 enzymes (CYPs). Some of their hydroxylation products were chemically synthesized and characterized by mass spectrometry to allow for their trace detection in urine samples. Following oral administration of metandienone or NorMD in one human volunteer each the post administration urines were checked for the presence of those hydroxylated metabolites using GC-MS/MS analysis.The human mitochondrial steroid hydroxylating enzymes CYP11B1 and CYP11B2 were capable to metabolize metandienone leading to the formation of 11β-hydroxymetandienone and 18-hydroxymetandienone. Following Wagner-Meerwein rearrangement, the resulting products could be assigned to 20βOH-NorMD and 11βOH-NorMD. The contribution of CYP11B1 and CYP11B2 in human metabolism of metandienone was confirmed by analysis of post-administration samples of metandienone and NorMD. Combined with the results from a previous study, enzymatic pathways were identified that involve CYP21 and CYP3A4 in the hydroxylation of NorMD, while CYP21, CYP3A4 and CYP11B2 take part in 20βOH-NorMD generation from MD.The current study represents a valuable contribution to the elucidation of clearance mechanisms of anabolic steroids and also indicates that mainly non-liver CYPs seem to be involved in these processes. © 2012 Elsevier Ireland Ltd.

Buchheit D.,PomBioTech GmbH | Dragan C.-A.,PomBioTech GmbH | Schmitt E.I.,PomBioTech GmbH | Bureik M.,PomBioTech GmbH
Drug Metabolism and Disposition | Year: 2011

UDP-glycosyltransferases (UGTs) are an important group of enzymes that participate in phase II metabolism of xenobiotics and use the cofactor UDP-glucuronic acid for the production of glucuronides. When acting on molecules bearing a carboxylic acid they can form acyl glucuronides, a group of metabolites that has gained significant interest in recent years because of concerns about their potential role in drug toxicity. In contrast, reports about the production of drug acyl glucosides (which might also display high reactivity) have been scarce. In this study, we discovered the formation of acyl glycoside metabolites of R- and S-ibuprofen (Ibu) by human liver microsomes supplied with the cofactor UDP-glucose. Subsequently, human UGT2B7*1 and UGT2B7*2 recombinantly expressed in fission yeast Schizosaccharomyces pombe could be shown to catalyze these reactions. Moreover, we could enhance the glucoside production rate in fission yeast by overexpressing the fission yeast gene SPCC1322.04, a potential UDP-glucose pyrophosphorylase (UGPase), but not by overexpression of SPCC794.10, and therefore suggest to name this gene fyu1 for fission yeast UGPase1. It was interesting to note that pronounced differences between the two polymorphic UGT2B7 variants were observed with respect to acyl glucoside production. Finally, using the metabolic precursor [ 13C 6]glucose, we demonstrated the production of stable isotope-labeled reference standards of Ibu acyl glucoside and Ibu acyl glucuronide by whole-cell biotransformation in fission yeast. Copyright © 2011 by The American Society for Pharmacology and Experimental Therapeutics.

Dragan C.-A.,PomBioTech GmbH | Buchheit D.,PomBioTech GmbH | Bischoff D.,Boehringer Ingelheim | Ebner T.,Boehringer Ingelheim | Bureik M.,PomBioTech GmbH
Drug Metabolism and Disposition | Year: 2010

Drug metabolites generated by UDP glycosyltransferases (UGTs) are needed for drug development and toxicity studies, especially in the context of safety testing of metabolites during drug development. Because chemical metabolite synthesis can be arduous, various biological approaches have been developed; however, no whole-cell biotransformation with recombinant microbes that express human UGTs was yet achieved. In this study we expressed human UDP glucose-6-dehydrogenase together with several human or rat UGT isoforms in the fission yeast Schizosaccharomyces pombe and generated strains that catalyze the whole-cell glucuronidation of standard substrates. Moreover, we established two methods to obtain stable isotope-labeled glucuronide metabolites: the first uses a labeled aglycon, whereas the second uses 13C6-glucose as a metabolic precursor of isotope-labeled UDP-glucuronic acid and yields a 6-fold labeled glucuronide. The system described here should lead to a significant facilitation in the production of both labeled and unlabeled drug glucuronides for industry and academia. © 2010 by The American Society for Pharmacology and Experimental Therapeutics.

Zehentgruber D.,Jülich Research Center | Dragan C.-A.,PomBioTech GmbH | Bureik M.,PomBioTech GmbH | Lutz S.,Jülich Research Center
Journal of Biotechnology | Year: 2010

Since cytochrome P450 monooxygenases enable the regio- and stereo-selective hydroxylation of C-H bonds, they are of outstanding interest for the synthesis of pharmaceuticals and fine chemicals. Nevertheless, for industrial applications of such enzymes, e.g., steroid hydroxylation, several challenges like cofactor and oxygen supply, limited stability and activity, or low substrate solubility have to be overcome. To identify the limiting factors in a P450 catalyzed whole cell biotransformation, 21-hydroxylation of 17-α-hydroxyprogesterone in Schizosacharomyces pombe expressing human CYP21 was chosen as model reaction. We report here that resting cells of this recombinant yeast strain can be used for efficient biotransformation. In the present study, we analyzed the intracellular redox cofactor pool of S. pombe by LC-MS/MS measurements and report the first quantification of the intracellular cofactor pool during P450 hydroxylation. Thereby a limitation caused by the redox cofactor could be excluded for resting cells. In contrary, low substrate solubility and its transport into the cell affect activity. Screening for an appropriate cosolvent identified methanol as the most promising candidate, since it showed the lowest inactivation effect on the biocatalyst. Through permeabilization of the membrane with the detergent tween 80 steroid hydroxylation activity increases, leading to a productivity of 540μM d -1 in a final batch experiment under optimized reaction conditions. © 2010 Elsevier B.V.

Zollner A.,PomBioTech GmbH | Buchheit D.,PomBioTech GmbH | Meyer M.R.,Saarland University | Maurer H.H.,Saarland University | And 2 more authors.
Bioanalysis | Year: 2010

Cytochrome P450 enzymes (CYPs or P450s) are the most important enzymes involved in the phase I metabolism of drugs and poisons in humans, while UDP glycosyltransferases catalyze the majority of phase II reactions. In addition, a number of other enzymes or enzyme families contribute to the metabolism of xenobiotica, including alcohol dehydrogenase, aldehyde dehydrogenase, ester and amide hydrolases, epoxide hydrolase and flavine monooxygenases, as well as sulfotransferases, catechol-O-methyltransferase and N-acetyltransferase. A thorough understanding of their activity and of the properties of the metabolites they form is an essential prerequisite for the assessment of drug-caused side effects or toxicity. In this context of MIST, efficient production systems are needed to permit the large-scale production of human drug metabolites. As classical chemical synthesis cannot always provide these metabolites, biotechnological approaches have been developed that typically employ the recombinant expression of human drug-metabolizing enzymes. This review summarizes the current knowledge regarding whole-cell biotransformation processes that make use of such an approach. © 2010 Future Science Ltd.

Naumann J.M.,PomBioTech GmbH | Messinger J.,Solvay Group | Bureik M.,PomBioTech GmbH
Journal of Biotechnology | Year: 2010

While phase I and phase II drug metabolites are important for drug development and toxicity studies, e.g. in the context of metabolites in safety testing (MIST), they are often not commercially available and their classical chemical synthesis can be cumbersome. Therefore, a biotechnological production of drug metabolites using microorganisms that recombinantly express human enzymes has been established in recent years. However, no whole-cell biotransformations that make use of human aldo-keto reductases (AKRs) have yet been reported. In this study, we have functionally expressed human AKR1C1 (20α-hydroxysteroid dehydrogenase) in the fission yeast Schizosaccharomyces pombe and demonstrate the ability of the resulting yeast strain to efficiently catalyze the reduction of progesterone or dydrogesterone to 20α-dihydroprogesterone (20α-DHP) and 20α-dihydrodydrogesterone (20α-DHD), respectively. The formation of any by-products or the occurrence of a back reaction were not detected. Seven other steroids with a 20-keto group (pregnenolone, 17α-hydroxyprogesterone, 11-deoxycortisol, cortisol, 11-deoxycorticosterone, corticosterone, and aldosterone) were not reduced by this system. At shaking flask scale we obtained conversion rates of 90 (±26) μM/d 20α-DHP and 244 (±93) μM/d 20α-dihydrodydrogesterone (20α-DHD), respectively. In a fed-batch fermentation under optimized reaction conditions an average 20α-DHP production rate of 300 μM/d was determined for a total biotransformation time of 72. h. We thus established an AKR-dependent whole-cell biotransformation process that can be used for production of human AKR metabolites on a large scale. © 2010 Elsevier B.V.

Naumann J.M.,PomBioTech GmbH | Kuttner G.,Humboldt University of Berlin | Bureik M.,PomBioTech GmbH
Applied Biochemistry and Biotechnology | Year: 2011

There is a rapidly growing demand for fluorescent single-chain Fv (scFv) antibody fragments for many applications. Yeasts have developed into attractive hosts for recombinant production of these functionalized proteins because they provide several advantages over prokaryotes and higher eukaryotes as expression systems, e.g., being capable of high-level secretion of heterologous proteins. In this study, we report Schizosaccharomyces pombe as a new host organism for secretory production of scFv-green fluorescent protein (GFP) fusions and compare it with previously described yeast expression systems. We cloned a plasmid for the expression and secretion of the anti-p24 (human immunodeficiency virus 1) CB4-1 scFv fused to GFP. After expression of the scFv-GFP fused to an N-terminal Cpy1 secretion signal sequence, fluorescence microscopy of living yeast cells indicated that the heterologous protein entered the secretory pathway. Western blot analysis of cell-free culture supernatants confirmed that the scFv-GFP was efficiently secreted with yields up to 5 mg/L. In addition, fluorescence measurements of culture supernatants demonstrated that the GFP moiety of the scFv-GFP protein is fully functional after secretion. Our data suggest that S. pombe has the potential for being used as alternative expression host in recombinant antibody fragment production by ensuring efficient protein processing and secretion. © 2010 Springer Science+Business Media, LLC.

Klein T.,Saarland University | Lange S.,Saarland University | Wilhelm N.,PomBioTech GmbH | Bureik M.,PomBioTech GmbH | And 3 more authors.
Metabolic Engineering | Year: 2014

Protein secretion in yeast is generally associated with a burden to cellular metabolism. To investigate this metabolic burden in Schizosaccharomyces pombe, we constructed a set of strains secreting the model protein maltase in different amounts. We quantified the influence of protein secretion on the metabolism applying 13C-based metabolic flux analysis in chemostat cultures. Analysis of the macromolecular biomass composition revealed an increase in cellular lipid content at elevated levels of protein secretion and we observed altered metabolic fluxes in the pentose phosphate pathway, the TCA cycle, and around the pyruvate node including mitochondrial NADPH supply. Supplementing acetate to glucose or glycerol minimal media was found to improve protein secretion, accompanied by an increased cellular lipid content and carbon flux through the TCA cycle as well as increased mitochondrial NADPH production. Thus, systematic metabolic analyses can assist in identifying factors limiting protein secretion and in deriving strategies to overcome these limitations. © 2013 International Metabolic Engineering Society.

Neunzig I.,Pom BioTech GmbH | Gohring A.,Pom BioTech GmbH | Dragan C.-A.,Pom BioTech GmbH | Zapp J.,Saarland University | And 3 more authors.
Journal of Biotechnology | Year: 2012

The anti-inflammatory drug ibuprofen (Ibu) is metabolized in the human liver to a number of metabolites including 1-hydroxyibuprofen (1-OH-Ibu), 2-OH-Ibu, and 3-OH-Ibu, respectively. The only human CYP known to produce relevant amounts of 3-OH-Ibu is CYP2C9 and as genetic polymorphisms of CYP2C9 influence the metabolization of numerous drugs, the availability of reference standards for CYP2C9-specific metabolites is of considerable interest. The aim of this study was to develop a biological production process for 3-OH-Ibu and to affirm its NMR characteristics. The recombinant fission yeast strain CAD68 coexpressing human CYP2C9 and CPR was used for the whole-cell biotransformation of Ibu to 3-OH-Ibu in 1. L batch-scale for 75. h. The average space-time yield for the bioproduction of 3-OH-Ibu (125± 34μmol/L. d) considerably exceeded that of 2-OH-Ibu (44 ± 10μmol/L. d). Accordingly, average biotransformation activities normalized to dry biomass weight were 5.0 ± 0.8μmol/g. d (3-OH-Ibu) and 1.9 ± 0.7μmol/g. d (2-OH-Ibu). The metabolite was prepurified on preparative TLC-plates, isolated by HPLC fractionation, and characterized by LC-MS and NMR. As expected, differential fragmentation patterns of 2-OH-Ibu and 3-OH-Ibu were detected in ESI-LC-MS analysis. 44. mg of 3-OH-Ibu was efficiently purified from four 1. L batch cultures and its structure was clearly confirmed by one- and two-dimensional NMR. © 2012 Elsevier B.V..

Buchheit D.,PomBioTech GmbH | Schmitt E.I.,PomBioTech GmbH | Bischoff D.,Boehringer Ingelheim | Ebner T.,Boehringer Ingelheim | Bureik M.,PomBioTech GmbH
Biological Chemistry | Year: 2011

Human UDP glycosyltransferases (UGTs) play an important role in xenobiotic detoxification. They increase the solubility of their substrates by adding a sugar moiety (such as glucuronic acid) to different functional entities (such as hydroxyl groups). The aim of this study was to investigate how glucuronidation of a standard substrate is affected by a change of the hetero-atom at the conjugation site. For this purpose, we compared the in vitro glucuronidation rates of 4-methylumbelliferone and 7-mercapto-4-methylcoumarin, respectively. Human liver microsomes catalyzed the S-glucuronidation of 7-mercapto-4- methylcoumarin almost as efficient as the O-glucuronidation of 4-methylumbelliferone. When testing isoenzyme specificity by whole cell biotransformation with fission yeast strains that recombinantly express all 19 human members of the UGT1 and UGT2 families, it was found that 13 isoenzymes were able to glucuronidate 7-mercapto-4-methylcoumarin, with five of them being specific for this substrate and the other eight also converting 4-methylumbelliferone under these conditions. The remaining six UGTs did not accept either substrate. Out of the eight isoenzymes that glucuronidated both substrates, four catalyzed both reactions approximately to the same extent, while three displayed higher conversion rates towards 4-methylumbelliferone and one preferred 7-mercapto-4-methylcoumarin. These data suggest that 7-mercapto-4-methylcoumarin is a convenient new standard substrate for monitoring S-glucuronidation. © 2011 by Walter de Gruyter Berlin Boston 2011.

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