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Esser-Skala W, Segl M, Wohlschlager T, Reisinger V, Holzmann J, Huber CG. Exploring sample preparation and data evaluation strategies for enhanced identification of host cell proteins in drug products of therapeutic antibodies and Fc-fusion proteins. Anal Bioanal Chem 2020; 412:6583-6593. [PMID: 32691086 PMCID: PMC7442769 DOI: 10.1007/s00216-020-02796-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/22/2020] [Accepted: 06/30/2020] [Indexed: 01/17/2023]
Abstract
Manufacturing of biopharmaceuticals involves recombinant protein expression in host cells followed by extensive purification of the target protein. Yet, host cell proteins (HCPs) may persist in the final drug product, potentially reducing its quality with respect to safety and efficacy. Consequently, residual HCPs are closely monitored during downstream processing by techniques such as enzyme-linked immunosorbent assay (ELISA) or high-performance liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS). The latter is especially attractive as it provides information with respect to protein identities. Although the applied HPLC-MS/MS methodologies are frequently optimized with respect to HCP identification, acquired data is typically analyzed using standard settings. Here, we describe an improved strategy for evaluating HPLC-MS/MS data of HCP-derived peptides, involving probabilistic protein inference and peptide detection in the absence of fragment ion spectra. This data analysis workflow was applied to data obtained for drug products of various biotherapeutics upon protein A affinity depletion. The presented data evaluation strategy enabled in-depth comparative analysis of the HCP repertoires identified in drug products of the monoclonal antibodies rituximab and bevacizumab, as well as the fusion protein etanercept. In contrast to commonly applied ELISA strategies, the here presented workflow is process-independent and may be implemented into existing HPLC-MS/MS setups for drug product characterization and process development. Graphical abstract ![]()
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Affiliation(s)
- Wolfgang Esser-Skala
- Bioanalytical Research Labs, Department of Biosciences, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
| | - Marius Segl
- Bioanalytical Research Labs, Department of Biosciences, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
| | - Therese Wohlschlager
- Bioanalytical Research Labs, Department of Biosciences, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
| | - Veronika Reisinger
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.,Technical Development Biosimilars, Global Drug Development, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Johann Holzmann
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.,Technical Development Biosimilars, Global Drug Development, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Christian G Huber
- Bioanalytical Research Labs, Department of Biosciences, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria. .,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.
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2
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Holzmann J, Politi AZ, Nagasaka K, Hantsche-Grininger M, Walther N, Koch B, Fuchs J, Dürnberger G, Tang W, Ladurner R, Stocsits RR, Busslinger GA, Novák B, Mechtler K, Davidson IF, Ellenberg J, Peters JM. Absolute quantification of cohesin, CTCF and their regulators in human cells. eLife 2019; 8:e46269. [PMID: 31204999 PMCID: PMC6606026 DOI: 10.7554/elife.46269] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/13/2019] [Indexed: 12/15/2022] Open
Abstract
The organisation of mammalian genomes into loops and topologically associating domains (TADs) contributes to chromatin structure, gene expression and recombination. TADs and many loops are formed by cohesin and positioned by CTCF. In proliferating cells, cohesin also mediates sister chromatid cohesion, which is essential for chromosome segregation. Current models of chromatin folding and cohesion are based on assumptions of how many cohesin and CTCF molecules organise the genome. Here we have measured absolute copy numbers and dynamics of cohesin, CTCF, NIPBL, WAPL and sororin by mass spectrometry, fluorescence-correlation spectroscopy and fluorescence recovery after photobleaching in HeLa cells. In G1-phase, there are ~250,000 nuclear cohesin complexes, of which ~ 160,000 are chromatin-bound. Comparison with chromatin immunoprecipitation-sequencing data implies that some genomic cohesin and CTCF enrichment sites are unoccupied in single cells at any one time. We discuss the implications of these findings for how cohesin can contribute to genome organisation and cohesion.
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Affiliation(s)
- Johann Holzmann
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna Biocenter (VBC)ViennaAustria
- Gregor Mendel Institute, Austrian Academy of SciencesVienna Biocenter (VBC)ViennaAustria
| | - Antonio Z Politi
- Cell Biology and Biophysics UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Kota Nagasaka
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
| | | | - Nike Walther
- Cell Biology and Biophysics UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Birgit Koch
- Cell Biology and Biophysics UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Johannes Fuchs
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna Biocenter (VBC)ViennaAustria
- Gregor Mendel Institute, Austrian Academy of SciencesVienna Biocenter (VBC)ViennaAustria
| | - Gerhard Dürnberger
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna Biocenter (VBC)ViennaAustria
- Gregor Mendel Institute, Austrian Academy of SciencesVienna Biocenter (VBC)ViennaAustria
| | - Wen Tang
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
| | - Rene Ladurner
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
| | - Roman R Stocsits
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
| | - Georg A Busslinger
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
| | - Béla Novák
- Department of BiochemistryUniversity of OxfordOxfordUnited Kingdom
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna Biocenter (VBC)ViennaAustria
- Gregor Mendel Institute, Austrian Academy of SciencesVienna Biocenter (VBC)ViennaAustria
| | - Iain Finley Davidson
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
| | - Jan Ellenberg
- Cell Biology and Biophysics UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP)Vienna Biocenter (VBC)ViennaAustria
- Medical University of ViennaViennaAustria
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3
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Regl C, Wohlschlager T, Esser-Skala W, Wagner I, Samonig M, Holzmann J, Huber CG. Dilute-and-shoot analysis of therapeutic monoclonal antibody variants in fermentation broth: a method capability study. MAbs 2019; 11:569-582. [PMID: 30668249 PMCID: PMC6512939 DOI: 10.1080/19420862.2018.1563034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Monoclonal antibodies (mAbs) are widely applied as highly specific and efficient therapeutic agents for various medical conditions, including cancer, inflammatory and autoimmune diseases. As protein production in cellular systems inherently generates a multitude of molecular variants, manufacturing of mAbs requires stringent control in order to ensure safety and efficacy of the drugs. Moreover, monitoring of mAb variants in the course of the fermentation process may allow instant tuning of process parameters to maintain optimal cell culture conditions. Here, we describe a fast and robust workflow for the characterization of mAb variants in fermentation broth. Sample preparation is minimal in that the fermentation broth is shortly centrifuged before dilution and HPLC-MS analysis in a short 15-min gradient run. In a single analysis, N-glycosylation and truncation variants of the expressed mAb are identified at the intact protein level. Simultaneously, absolute quantification of mAb content in fermentation broth is achieved. The whole workflow features excellent robustness as well as retention time and peak area stability. Additional enzymatic removal of N-glycans enables determination of mAb glycation levels, which are subsequently considered in relative N-glycoform quantification to correct for isobaric galactosylation. Several molecular attributes of the expressed therapeutic protein may thus be continuously monitored to ensure the desired product profile. Application of the described workflow in an industrial environment may therefore substantially enhance in-process control in mAb production, as well as targeted biosimilar development.
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Affiliation(s)
- Christof Regl
- a Department of Biosciences, Bioanalytical Research Labs , University of Salzburg , Salzburg , Austria.,b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria
| | - Therese Wohlschlager
- a Department of Biosciences, Bioanalytical Research Labs , University of Salzburg , Salzburg , Austria.,b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria
| | - Wolfgang Esser-Skala
- a Department of Biosciences, Bioanalytical Research Labs , University of Salzburg , Salzburg , Austria.,b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria
| | - Iris Wagner
- a Department of Biosciences, Bioanalytical Research Labs , University of Salzburg , Salzburg , Austria.,b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria
| | - Martin Samonig
- a Department of Biosciences, Bioanalytical Research Labs , University of Salzburg , Salzburg , Austria.,b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria.,c Thermo Fisher Scientific GmbH , Germering , Germany
| | - Johann Holzmann
- b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria.,d Technical Development Biosimilars , Global Drug Development, Novartis, Sandoz GmbH , Kundl , Austria
| | - Christian G Huber
- a Department of Biosciences, Bioanalytical Research Labs , University of Salzburg , Salzburg , Austria.,b Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization , University of Salzburg , Salzburg , Austria
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4
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Vilardo E, Nachbagauer C, Buzet A, Taschner A, Holzmann J, Rossmanith W. A subcomplex of human mitochondrial RNase P is a bifunctional methyltransferase - extensive moonlighting in mitochondrial tRNA biogenesis. Nucleic Acids Res 2018; 46:11126-11127. [PMID: 30295808 PMCID: PMC6237747 DOI: 10.1093/nar/gky931] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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5
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Wohlschlager T, Scheffler K, Forstenlehner IC, Skala W, Senn S, Damoc E, Holzmann J, Huber CG. Native mass spectrometry combined with enzymatic dissection unravels glycoform heterogeneity of biopharmaceuticals. Nat Commun 2018; 9:1713. [PMID: 29712889 PMCID: PMC5928108 DOI: 10.1038/s41467-018-04061-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 03/30/2018] [Indexed: 12/18/2022] Open
Abstract
Robust manufacturing processes resulting in consistent glycosylation are critical for the efficacy and safety of biopharmaceuticals. Information on glycosylation can be obtained by conventional bottom–up methods but is often limited to the glycan or glycopeptide level. Here, we apply high-resolution native mass spectrometry (MS) for the characterization of the therapeutic fusion protein Etanercept to unravel glycoform heterogeneity in conditions of hitherto unmatched mass spectral complexity. Higher spatial resolution at lower charge states, an inherent characteristic of native MS, represents a key component for the successful revelation of glycan heterogeneity. Combined with enzymatic dissection using a set of proteases and glycosidases, assignment of specific glycoforms is achieved by transferring information from subunit to whole protein level. The application of native mass spectrometric analysis of intact Etanercept as a fingerprinting tool for the assessment of batch-to-batch variability is exemplified and may be extended to demonstrate comparability after changes in the biologic manufacturing process. The specific glycosylation patterns of biological drugs often impact the efficacy and safety of the therapeutic product. Here the authors describe a native mass spectrometry approach that allows the resolution of highly complex glycosylation patterns on large proteins, which they apply to the therapeutic Fc-fusion protein Etanercept.
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Affiliation(s)
- Therese Wohlschlager
- Department of Biosciences, Bioanalytical Research Labs, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Kai Scheffler
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Thermo Fisher Scientific GmbH, Dornierstraße 4, 82110, Germering, Germany
| | - Ines C Forstenlehner
- Department of Biosciences, Bioanalytical Research Labs, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Technical Development Biosimilars, Global Drug Development, Novartis, Sandoz GmbH, Biochemiestrasse 10, 6250, Kundl, Austria
| | - Wolfgang Skala
- Department of Biosciences, Bioanalytical Research Labs, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Stefan Senn
- Department of Biosciences, Bioanalytical Research Labs, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Eugen Damoc
- Thermo Fisher Scientific GmbH, Hanna-Kunath-Strasse 11, 28199, Bremen, Germany
| | - Johann Holzmann
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.,Technical Development Biosimilars, Global Drug Development, Novartis, Sandoz GmbH, Biochemiestrasse 10, 6250, Kundl, Austria
| | - Christian G Huber
- Department of Biosciences, Bioanalytical Research Labs, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria. .,Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria.
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6
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Lamanna WC, Holzmann J, Cohen HP, Guo X, Schweigler M, Stangler T, Seidl A, Schiestl M. Maintaining consistent quality and clinical performance of biopharmaceuticals. Expert Opin Biol Ther 2018; 18:369-379. [DOI: 10.1080/14712598.2018.1421169] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
| | - Johann Holzmann
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Kundl, Austria
| | | | - Xinghua Guo
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Kundl, Austria
| | - Monika Schweigler
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Kundl, Austria
| | - Thomas Stangler
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Kundl, Austria
| | - Andreas Seidl
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Hexal AG, Oberhaching, Germany
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7
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Regl C, Wohlschlager T, Holzmann J, Huber CG. A Generic HPLC Method for Absolute Quantification of Oxidation in Monoclonal Antibodies and Fc-Fusion Proteins Using UV and MS Detection. Anal Chem 2017; 89:8391-8398. [DOI: 10.1021/acs.analchem.7b01755] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Christof Regl
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
- Christian
Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
| | - Therese Wohlschlager
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
- Christian
Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
| | - Johann Holzmann
- Christian
Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
- Technical
Development
Biosimilars, Physicochemical Characterization Kundl, Novartis BTDM,
Sandoz GmbH, Biochemiestrasse 10, 6250 Kundl, Austria
| | - Christian G. Huber
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
- Christian
Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria
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8
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Lamanna WC, Mayer RE, Rupprechter A, Fuchs M, Higel F, Fritsch C, Vogelsang C, Seidl A, Toll H, Schiestl M, Holzmann J. The structure-function relationship of disulfide bonds in etanercept. Sci Rep 2017. [PMID: 28638112 PMCID: PMC5479810 DOI: 10.1038/s41598-017-04320-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Etanercept is a TNFα receptor Fc fusion protein used for the treatment of rheumatic disease and psoriasis. Physicochemical and functional investigation of process fractions during development of the etanercept biosimilar GP2015 (Erelzi®) revealed a correlation between reduced potency and incorrect disulfide bridging between specific cysteines in the receptor domain. This novel structure-function relationship was found to be the molecular basis for reduced potency in recent Enbrel® batches, which exhibit higher levels of incorrect disulfide bridging. Interestingly, incorrect disulfide bridging was found to be reversible under serum-like redox conditions, restoring potency to normal levels. This redox dependent reversibility suggests that these variants are likely not relevant for clinical efficacy once the drug enters the bloodstream. Nonetheless, incorrect disulfide bridging in etanercept represents a new quality attribute that is critical for biopharmaceutical functionality and should thus be carefully monitored and controlled to guarantee patient safety.
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Affiliation(s)
- William C Lamanna
- Sandoz Biopharmaceuticals, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Robert Ernst Mayer
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Alfred Rupprechter
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Michael Fuchs
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Fabian Higel
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Hexal AG, Keltenring 1+3, 82041, Oberhaching, Germany
| | | | - Cornelia Vogelsang
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Andreas Seidl
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Hexal AG, Keltenring 1+3, 82041, Oberhaching, Germany
| | - Hansjoerg Toll
- Sandoz Biopharmaceuticals, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Martin Schiestl
- Sandoz Biopharmaceuticals, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria
| | - Johann Holzmann
- Technical Development Biosimilars, Biologics Technical Development and Manufacturing, Novartis, Sandoz GmbH, Biochemiestraße 10, 6250, Kundl, Austria.
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10
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Sörgel F, Schwebig A, Holzmann J, Prasch S, Singh P, Kinzig M. Comparability of biosimilar filgrastim with originator filgrastim: protein characterization, pharmacodynamics, and pharmacokinetics. BioDrugs 2015; 29:123-31. [PMID: 25837839 PMCID: PMC4412827 DOI: 10.1007/s40259-015-0124-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Background Biosimilars provide safety, purity, and potency similar to those of a reference biologic product. Methods An array of protein analytical techniques was used to compare the physicochemical properties of proposed biosimilar filgrastim (EP2006), US-approved originator filgrastim, and EU-approved originator filgrastim. Biological characterization involved surface plasmon resonance spectroscopy analyses and in vitro proliferation assays. A randomized, double-blind, two-way crossover, phase I study in healthy volunteers assessed the pharmacodynamics, pharmacokinetics, and safety profiles of EP2006 and US-approved originator filgrastim (administered as a single subcutaneous 10 µg/kg injection). Results EP2006 and originator filgrastim (US and EU approved) were highly similar with respect to primary, secondary, and tertiary protein structures; mass, size, purity, charge, and hydrophobicity. No differences in receptor binding affinity were observed, and all samples demonstrated similar in vitro bioactivity. In the phase I study, no statistically significant differences between EP2006 and US-approved originator filgrastim were noted in pharmacodynamic or pharmacokinetic parameters, and all confidence intervals were within the equivalence boundaries. The two products had similar safety profiles. Conclusion These studies provide robust evidence of the structural and functional similarity between the proposed biosimilar filgrastim (EP2006) and the US-approved originator filgrastim.
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Affiliation(s)
- Fritz Sörgel
- IBMP-Institute for Biomedical and Pharmaceutical Research, Paul-Ehrlich-Strasse 19, 90562, Nürnberg-Heroldsberg, Germany,
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Forstenlehner IC, Holzmann J, Toll H, Huber CG. Site-Specific Characterization and Absolute Quantification of Pegfilgrastim Oxidation by Top-Down High-Performance Liquid Chromatography–Mass Spectrometry. Anal Chem 2015; 87:9336-43. [DOI: 10.1021/acs.analchem.5b02029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ines C. Forstenlehner
- Christian
Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Johann Holzmann
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
- Analytical
Characterization Biopharmaceuticals, Sandoz GmbH, Biochemiestrasse
10, 6250 Kundl, Austria
| | - Hansjörg Toll
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
- Analytical
Characterization Biopharmaceuticals, Sandoz GmbH, Biochemiestrasse
10, 6250 Kundl, Austria
| | - Christian G. Huber
- Christian
Doppler Laboratory for Innovative Tools for Biosimilar Characterization, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
- Department
of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
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12
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Forstenlehner IC, Holzmann J, Scheffler K, Wieder W, Toll H, Huber CG. A direct-infusion- and HPLC-ESI-Orbitrap-MS approach for the characterization of intact PEGylated proteins. Anal Chem 2013; 86:826-34. [PMID: 24308604 DOI: 10.1021/ac403390y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The characterization of proteins modified with poly(ethylene glycol) (PEG), such as recombinant human granulocyte-colony stimulating factor (PEGylated rhG-CSF or pegfilgrastim), by electrospray ionization-mass spectrometry (ESI-MS) constitutes a challenge due to the overlapping protein charge state pattern and PEG polydispersity. In order to minimize spectral overlaps, charge reduction by means of the addition of amine was applied. Method development for direct-infusion measurements, carried out on an ESI-time-of-flight (ESI-TOF) instrument, demonstrated the potential of triethylamine (TEA) for shifting the charge state pattern toward lower-charged species and of formic acid (FA) for causing higher charging. After successful method transfer to the LTQ Orbitrap XL instrument, isotopically resolved mass spectra could be acquired. With a median mass accuracy of 1.26 ppm, a number-average monoisotopic molecular mass of 40074.64 Da was determined for pegfilgrastim. The direct comparison of three Orbitrap mass spectrometers, namely the LTQ Orbitrap XL, the Exactive, and the Q Exactive, demonstrated that online interfacing to high performance liquid chromatography (HPLC) was only feasible with the Q Exactive, which offers adequate spectral quality on a time scale compatible with chromatographic separation (i.e., 0.2 min acquisition time per chromatographic peak). Finally, the applicability of both direct-infusion Orbitrap MS and HPLC interfaced to Orbitrap MS was demonstrated for the detection of methionine oxidation in pegfilgrastim. Singly, doubly, and triply oxidized species were readily resolved in the chromatogram, while their oxidation status was easily determined from the mass shifts observed in the deconvoluted mass spectra.
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Affiliation(s)
- Ines C Forstenlehner
- Department of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg , Hellbrunnerstrasse 34, 5020 Salzburg, Austria
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Holzmann J, Hausberger A, Rupprechter A, Toll H. Top-down MS for rapid methionine oxidation site assignment in filgrastim. Anal Bioanal Chem 2013; 405:6667-74. [PMID: 23831755 PMCID: PMC3730093 DOI: 10.1007/s00216-013-7138-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/07/2013] [Accepted: 06/10/2013] [Indexed: 11/30/2022]
Abstract
Protein therapeutics have emerged as a major new class of pharmaceuticals. One important shelf-life-limiting factor of biopharmaceuticals is methionine oxidation, and therefore, it is important that analytical methods are able to thoroughly characterize all possible oxidized variants. Here, we present a fast and sensitive method to perform online methionine oxidation site assignment using granulocyte colony-stimulating factor (filgrastim) as a model. The method is based on top-down MS using the all-ion fragmentation mode of the Exactive benchtop mass spectrometer. Conditions that provide information on the intact mass of the protein as well as on fragment ions that allow unambiguous site assignment of methionine oxidation in filgrastim variants as low as 0.12 % of total peak area in a chromatographic time scale were identified. Using this method, we performed methionine oxidation site assignment in H2O2-stressed filgrastim and in filgrastim which was stored at intended conditions, respectively. We show that the relative abundance of oxidation species observed in filgrastim stored under intended conditions differs strikingly from the oxidized species observed after H2O2 stress. Additionally, we report an oxidized filgrastim variant that has not been previously described in the literature. A top-down approach on an Exactive benchtop mass spectrometer in all-ion fragmentation mode is a highly attractive alternative to the traditional approach of isolation/bottom-up analysis for methionine oxidation site assignement in biopharmaceuticals. With a sensitivity as low as 0.12 % of total peak area and a throughput of about one sample per hour, the method is highly suitable for a thorough characterization of oxidized methionine residues ![]()
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14
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Vilardo E, Nachbagauer C, Buzet A, Taschner A, Holzmann J, Rossmanith W. A subcomplex of human mitochondrial RNase P is a bifunctional methyltransferase--extensive moonlighting in mitochondrial tRNA biogenesis. Nucleic Acids Res 2012; 40:11583-93. [PMID: 23042678 PMCID: PMC3526285 DOI: 10.1093/nar/gks910] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Transfer RNAs (tRNAs) reach their mature functional form through several steps of processing and modification. Some nucleotide modifications affect the proper folding of tRNAs, and they are crucial in case of the non-canonically structured animal mitochondrial tRNAs, as exemplified by the apparently ubiquitous methylation of purines at position 9. Here, we show that a subcomplex of human mitochondrial RNase P, the endonuclease removing tRNA 5′ extensions, is the methyltransferase responsible for m1G9 and m1A9 formation. The ability of the mitochondrial tRNA:m1R9 methyltransferase to modify both purines is uncommon among nucleic acid modification enzymes. In contrast to all the related methyltransferases, the human mitochondrial enzyme, moreover, requires a short-chain dehydrogenase as a partner protein. Human mitochondrial RNase P, thus, constitutes a multifunctional complex, whose subunits moonlight in cascade: a fatty and amino acid degradation enzyme in tRNA methylation and the methyltransferase, in turn, in tRNA 5′ end processing.
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Affiliation(s)
- Elisa Vilardo
- Center for Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
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15
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Holzmann J, Fuchs J, Pichler P, Peters JM, Mechtler K. Lesson from the stoichiometry determination of the cohesin complex: a short protease mediated elution increases the recovery from cross-linked antibody-conjugated beads. J Proteome Res 2011; 10:780-9. [PMID: 21043528 PMCID: PMC3033704 DOI: 10.1021/pr100927x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Indexed: 12/17/2022]
Abstract
Affinity purification of proteins using antibodies coupled to beads and subsequent mass spectrometric analysis has become a standard technique for the identification of protein complexes. With the recent transfer of the isotope dilution mass spectrometry principle (IDMS) to the field of proteomics, quantitative analyses-such as the stoichiometry determination of protein complexes-have become achievable. Traditionally proteins were eluted from antibody-conjugated beads using glycine at low pH or using diluted acids such as HCl, TFA, or FA, but elution was often found to be incomplete. Using the cohesin complex and the anaphase promoting complex/cyclosome (APC/C) as examples, we show that a short 15-60 min predigestion with a protease such as LysC (modified on-bead digest termed protease elution) increases the elution efficiency 2- to 3-fold compared to standard acid elution protocols. While longer incubation periods-as performed in standard on-bead digestion-led to partial proteolysis of the cross-linked antibodies, no or only insignificant cleavage was observed after 15-60 min protease mediated elution. Using the protease elution method, we successfully determined the stoichiometry of the cohesin complex by absolute quantification of the four core subunits using LC-SRM analysis and 19 reference peptides generated with the EtEP strategy. Protease elution was 3-fold more efficient compared to HCl elution, but measurements using both elution techniques are in agreement with a 1:1:1:1 stoichiometry. Furthermore, using isoform specific reference peptides, we determined the exact STAG1:STAG2 stoichiometry within the population of cohesin complexes. In summary, we show that the protease elution protocol increases the recovery from affinity beads and is compatible with quantitative measurements such as the stoichiometry determination of protein complexes.
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Affiliation(s)
- Johann Holzmann
- Research Institute of Molecular Pathology (IMP), Vienna, Austria.
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16
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Pichler P, Köcher T, Holzmann J, Möhring T, Ammerer G, Mechtler K. Improved precision of iTRAQ and TMT quantification by an axial extraction field in an Orbitrap HCD cell. Anal Chem 2011; 83:1469-74. [PMID: 21275378 PMCID: PMC3270567 DOI: 10.1021/ac102265w] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
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Improving analytical precision is a major goal in quantitative differential proteomics as high precision ensures low numbers of outliers, a source of false positives with regard to quantification. In addition, higher precision increases statistical power, i.e., the probability to detect significant differences. With chemical labeling using isobaric tags for relative and absolute quantitation (iTRAQ) or tandem mass tag (TMT) reagents, quantification is based on the extraction of reporter ions from tandem mass spectrometry (MS/MS) spectra. We compared the performance of two versions of the LTQ Orbitrap higher energy collisional dissociation (HCD) cell with and without an axial electric field with regard to reporter ion quantification. The HCD cell with the axial electric field was designed to push fragment ions into the C-trap and this version is mounted in current Orbitrap XL ETD and Orbitrap Velos instruments. Our goal was to evaluate whether the purported improvement in ion transmission had a measurable impact on the precision of MS/MS based quantification using peptide labeling with isobaric tags. We show that the axial electric field led to an increased percentage of HCD spectra in which the complete set of reporter ions was detected and, even more important, to a reduction in overall variance, i.e., improved analytical precision of the acquired data. Notably, adequate precision of HCD-based quantification was maintained even for low precursor ion intensities of a complex biological sample. These findings may help researchers in their design of quantitative proteomics studies using isobaric tags and establish HCD-based quantification on the LTQ Orbitrap as a highly precise approach in quantitative proteomics.
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Affiliation(s)
- Peter Pichler
- Christian Doppler Laboratory for Proteome Analysis, University of Vienna, Vienna, Austria.
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17
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Pichler P, Köcher T, Holzmann J, Mazanek M, Taus T, Ammerer G, Mechtler K. Peptide labeling with isobaric tags yields higher identification rates using iTRAQ 4-plex compared to TMT 6-plex and iTRAQ 8-plex on LTQ Orbitrap. Anal Chem 2010; 82:6549-58. [PMID: 20593797 PMCID: PMC3093924 DOI: 10.1021/ac100890k] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptide labeling with isobaric tags has become a popular technique in quantitative shotgun proteomics. Using two different samples viz. a protein mixture and HeLa extracts, we show that three commercially available isobaric tags differ with regard to peptide identification rates: The number of identified proteins and peptides was largest with iTRAQ 4-plex, followed by TMT 6-plex, and smallest with iTRAQ 8-plex. In all experiments, we employed a previously described method where two scans were acquired for each precursor on an LTQ Orbitrap: A CID scan under standard settings for identification, and a HCD scan for quantification. The observed differences in identification rates were similar when data was searched with either Mascot or Sequest. We consider these findings to be the result of a combination of several factors, most notably prominent ions in CID spectra as a consequence of loss of fragments of the label tag from precursor ions. These fragment ions cannot be explained by current search engines and were observed to have a negative impact on peptide scores.
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Affiliation(s)
- Peter Pichler
- Christian Doppler Laboratory for Proteome Analysis, University of Vienna, Austria.
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18
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Stasyk T, Holzmann J, Stumberger S, Ebner HL, Hess MW, Bonn GK, Mechtler K, Huber LA. Proteomic analysis of endosomes from genetically modified p14/MP1 mouse embryonic fibroblasts. Proteomics 2010; 10:4117-27. [PMID: 21080497 DOI: 10.1002/pmic.201000258] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The p14/MP1 scaffold complex binds MEK1 and ERK1/2 on late endosomes, thus regulating the strength, duration and intracellular location of MAPK signaling. By organelle proteomics we have compared the protein composition of endosomes purified from genetically modified p14⁻/⁻, p14+/⁻ and p14(rev) mouse embryonic fibroblasts. The latter ones were reconstituted retrovirally from p14⁻/⁻ mouse embryonic fibroblasts by reexpression of pEGFP-p14 at equimolar ratios with its physiological binding partner MP1, as shown here by absolute quantification of MP1 and p14 proteins on endosomes by quantitative MS using the Equimolarity through Equalizer Peptide strategy. A combination of subcellular fractionation, 2-D DIGE and MALDI-TOF/TOF MS revealed 31 proteins differentially regulated in p14⁻/⁻ organelles, which were rescued by reexpression of pEGFP-p14 in p14⁻/⁻ endosomes. Regulated proteins are known to be involved in actin remodeling, endosomal signal transduction and trafficking. Identified proteins and their in silico interaction networks suggested that endosomal signaling might regulate such major cellular functions such as proliferation, differentiation, migration and survival.
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Affiliation(s)
- Taras Stasyk
- Biocenter, Division of Cell Biology, Innsbruck Medical University, Innsbruck, Austria
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Gobert A, Gutmann B, Taschner A, Gössringer M, Holzmann J, Hartmann RK, Rossmanith W, Giegé P. A single Arabidopsis organellar protein has RNase P activity. Nat Struct Mol Biol 2010; 17:740-4. [PMID: 20473316 DOI: 10.1038/nsmb.1812] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 03/19/2010] [Indexed: 12/18/2022]
Abstract
The ubiquitous endonuclease RNase P is responsible for the 5' maturation of tRNA precursors. Until the discovery of human mitochondrial RNase P, these enzymes had typically been found to be ribonucleoproteins, the catalytic activity of which is associated with the RNA component. Here we show that, in Arabidopsis thaliana mitochondria and plastids, a single protein called 'proteinaceous RNase P' (PRORP1) can perform the endonucleolytic maturation of tRNA precursors that defines RNase P activity. In addition, PRORP1 is able to cleave tRNA-like structures involved in the maturation of plant mitochondrial mRNAs. Finally, we show that Arabidopsis PRORP1 can replace the bacterial ribonucleoprotein RNase P in Escherichia coli cells. PRORP2 and PRORP3, two paralogs of PRORP1, are both localized in the nucleus.
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Affiliation(s)
- Anthony Gobert
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Strasbourg, France
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Holzmann J, Pichler P, Madalinski M, Kurzbauer R, Mechtler K. Stoichiometry Determination of the MP1−p14 Complex Using a Novel and Cost-Efficient Method To Produce an Equimolar Mixture of Standard Peptides. Anal Chem 2009; 81:10254-61. [DOI: 10.1021/ac902286m] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Johann Holzmann
- Research Institute of Molecular Pathology (IMP), CD-Laboratory for Proteome Analysis, and Institute of Molecular Biotechnology (IMBA), 1030 Vienna, Austria
| | - Peter Pichler
- Research Institute of Molecular Pathology (IMP), CD-Laboratory for Proteome Analysis, and Institute of Molecular Biotechnology (IMBA), 1030 Vienna, Austria
| | - Mathias Madalinski
- Research Institute of Molecular Pathology (IMP), CD-Laboratory for Proteome Analysis, and Institute of Molecular Biotechnology (IMBA), 1030 Vienna, Austria
| | - Robert Kurzbauer
- Research Institute of Molecular Pathology (IMP), CD-Laboratory for Proteome Analysis, and Institute of Molecular Biotechnology (IMBA), 1030 Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), CD-Laboratory for Proteome Analysis, and Institute of Molecular Biotechnology (IMBA), 1030 Vienna, Austria
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Holzmann J, Appelhagen A, Ludwig R. Correlation of Static and Dynamic Heterogeneities in Supercooled Water by Means of Molecular Dynamics Simulations. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2009.6065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The unusual increase of diffusivity of supercooled water upon compression seems to be related to the existence of at least two major distinct local structural forms: a "low-density" structure, exhibiting an almost perfect tetrahedral hydrogen bonding network, and a "high-density" structure, characterized by defects in this network. The structural changes can be measured by the "tetrahedricity parameter", describing the deviation from the ideal tetrahedron. In this paper we show that the anomalous diffusion behavior upon compression cannot only be related to the structural heterogeneities but also to dynamical heterogeneities occuring in supercooled liquid water. This is shown for translational heterogeneities which decrease with temperature and pressure. Both, static and dynamic heterogeneities can be correlated. They are substantial at low temperatures and moderate pressures and diminish with increasing temperature and pressure, respectively. Our results are based on molecular dynamics simulations of the TIP4P-Ew water model [1].
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Abstract
While the principal mode of synthesis of the different human mitochondrial RNA species was recognized almost three decades ago, the constituents of one of the key players of the postulated RNA processing machinery were identified only recently. Human mitochondrial RNase P, the endonuclease responsible for tRNA 5' end maturation, turned out to be unlike any of its previously characterized cousins. It is not only devoid of the RNA moiety thought to be diagnostic of this type of enzymes so far, but it is instead built like a patchwork of multifunctional proteins coming together to moonlight in tRNA 5' end cleavage.
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Affiliation(s)
- Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna, Austria.
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23
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Holzmann J, Frank P, Löffler E, Bennett KL, Gerner C, Rossmanith W. RNase P without RNA: identification and functional reconstitution of the human mitochondrial tRNA processing enzyme. Cell 2008; 135:462-74. [PMID: 18984158 DOI: 10.1016/j.cell.2008.09.013] [Citation(s) in RCA: 421] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 07/17/2008] [Accepted: 09/02/2008] [Indexed: 11/26/2022]
Abstract
tRNAs are synthesized as immature precursors, and on their way to functional maturity, extra nucleotides at their 5' ends are removed by an endonuclease called RNase P. All RNase P enzymes characterized so far are composed of an RNA plus one or more proteins, and tRNA 5' end maturation is considered a universal ribozyme-catalyzed process. Using a combinatorial purification/proteomics approach, we identified the components of human mitochondrial RNase P and reconstituted the enzymatic activity from three recombinant proteins. We thereby demonstrate that human mitochondrial RNase P is a protein enzyme that does not require a trans-acting RNA component for catalysis. Moreover, the mitochondrial enzyme turns out to be an unexpected type of patchwork enzyme, composed of a tRNA methyltransferase, a short-chain dehydrogenase/reductase-family member, and a protein of hitherto unknown functional and evolutionary origin, possibly representing the enzyme's metallonuclease moiety. Apparently, animal mitochondria lost the seemingly ubiquitous RNA world remnant after reinventing RNase P from preexisting components.
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Affiliation(s)
- Johann Holzmann
- Center for Anatomy & Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
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Brandl N, Holzmann J, Schabus R, Huettinger M. Effects of chondroitin sulfate on the cellular metabolism. Adv Pharmacol 2007; 53:433-47. [PMID: 17239779 DOI: 10.1016/s1054-3589(05)53021-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Affiliation(s)
- N Brandl
- Medical University Vienna, Center Physiology and Pathophysiology, 1090 Vienna, Währingerstrasse 10 Austria
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Holzmann J, Brandl N, Zemann A, Schabus R, Marlovits S, Cowburn R, Huettinger M. Assorted effects of TGFbeta and chondroitinsulfate on p38 and ERK1/2 activation levels in human articular chondrocytes stimulated with LPS. Osteoarthritis Cartilage 2006; 14:519-25. [PMID: 16503173 DOI: 10.1016/j.joca.2005.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Accepted: 12/17/2005] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Inadequate cellular response of chondrocytes to stress frequently terminates in osteoarthritis (OA). Adequate response is fundamentally modulated by concerted cytokine signaling events, directing degradation and synthesis of cartilage on articular surfaces where and whenever necessary. Transforming growth factor (TGF)beta is a prominent mediator in cartilage anabolism, although particular catabolic activities are occasionally reported. Clearly, before the TGFbeta signal gets through to the gene regulatory machinery, cross talk with modulators occurs. METHOD We tested the hypothesis whether chondroitinsulfate (CS) modulates cell signaling. TGFbeta and/or soluble CS was added to human articular chondrocytes (HACs) and activation of p38 and extracellular signal related kinase (ERK)1/2 was determined by immunoblot analysis. Expression levels of mRNA of matrix metalloproteinase (MMP)-2, -3 and -13 were determined by real-time polymerase chain reaction (PCR). RESULTS No significant effects were observed unless cells were stimulated with lipopolysaccharide (LPS), invigorating catabolic metabolism in chondrocytes. LPS effects, however, were profoundly modulated by TGFbeta, CS and both applied in combination. Most prominent, the silencing of p38 stress signal by CS was superimposable to that of TGFbeta. Phospho-ERK1/2 levels were raised by TGFbeta three-fold over LPS induced levels. In contrast, CS treatment, alone or combined with TGFbeta, reduced phosphorylation significantly below LPS induced levels. Finally, suppression of LPS induced MMP-13 mRNA levels resulted with CS. CONCLUSION Soluble CS modulates signaling events in chondrocytes concurrent with MMP-13 down regulation. The effects observed suggest a feedback signaling mechanism cross talking with TGFbeta-signal pathways and may serve an explanation, on the cellular level, for the beneficial effects found in clinical studies with pharmacologic application of CS.
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Affiliation(s)
- J Holzmann
- Zentrum Physiology and Pathophysiology, A-1090 Wien, Währingerstr. 10/13, Austria
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Hodge E, Banowsky L, Novick A, Lewis R, Streem S, Steinmuller D, Holzmann J, McFarlin L, Graneto D, Medendorp SV. Alternative immunosuppressive strategies in the management of recipients of living related renal transplants. Transplant Proc 1989; 21:1609-14. [PMID: 2652524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- E Hodge
- Department of Urology, Humana Hospital San Antonio, Texas
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