1
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Pouyan P, Zemella A, Schloßhauer JL, Walter RM, Haag R, Kubick S. One to one comparison of cell-free synthesized erythropoietin conjugates modified with linear polyglycerol and polyethylene glycol. Sci Rep 2023; 13:6394. [PMID: 37076514 PMCID: PMC10115831 DOI: 10.1038/s41598-023-33463-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023] Open
Abstract
With more than 20 Food and Drug Administration (FDA)-approved poly (ethylene glycol) (PEG) modified drugs on the market, PEG is the gold standard polymer in bioconjugation. The coupling improves stability, efficiency and can prolong blood circulation time of therapeutic proteins. Even though PEGylation is described as non-toxic and non-immunogenic, reports accumulate with data showing allergic reactions to PEG. Since PEG is not only applied in therapeutics, but can also be found in foods and cosmetics, anti-PEG-antibodies can occur even without a medical treatment. Hypersensitivity to PEG thereby can lead to a reduced drug efficiency, fast blood clearance and in rare cases anaphylactic reactions. Therefore, finding alternatives for PEG is crucial. In this study, we present linear polyglycerol (LPG) for bioconjugation as an alternative polymer to PEG. We report the conjugation of LPG and PEG by click-chemistry to the glycoprotein erythropoietin (EPO), synthesized in a eukaryotic cell-free protein synthesis system. Furthermore, the influence of the polymers on EPOs stability and activity on a growth hormone dependent cell-line was evaluated. The similar characteristics of both bioconjugates show that LPGylation can be a promising alternative to PEGylation.
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Affiliation(s)
- Paria Pouyan
- Institut for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195, Berlin, Germany
| | - Anne Zemella
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany.
| | - Jeffrey L Schloßhauer
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
- Institute of Chemistry and Biochemistry-Biochemistry, Freie Universität Berlin, Takustr. 6, 14195, Berlin, Germany
| | - Ruben M Walter
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
- Institute of Biotechnology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - Rainer Haag
- Institut for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195, Berlin, Germany.
| | - Stefan Kubick
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
- Institute of Chemistry and Biochemistry-Biochemistry, Freie Universität Berlin, Takustr. 6, 14195, Berlin, Germany
- Faculty of Health Sciences, oint Faculty of the Brandenburg University of Technology Cottbus-Senftenberg, the Brandenburg Medical School Theodor Fontane and the University of Potsdam, Potsdam, Germany
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2
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Moncalvo F, Lacroce E, Franzoni G, Altomare A, Fasoli E, Aldini G, Sacchetti A, Cellesi F. Selective Protein Conjugation of Poly(glycerol monomethacrylate) and Poly(polyethylene glycol methacrylate) with Tunable Topology via Reductive Amination with Multifunctional ATRP Initiators for Activity Preservation. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Filippo Moncalvo
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, via Mancinelli 7, Milano 20131, Italy
| | - Elisa Lacroce
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, via Mancinelli 7, Milano 20131, Italy
| | - Giulia Franzoni
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, via Mancinelli 7, Milano 20131, Italy
| | - Alessandra Altomare
- Department of Pharmaceutical Sciences (DISFARM), University of Milan, 20133 Milan, Italy
| | - Elisa Fasoli
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, via Mancinelli 7, Milano 20131, Italy
| | - Giancarlo Aldini
- Department of Pharmaceutical Sciences (DISFARM), University of Milan, 20133 Milan, Italy
| | - Alessandro Sacchetti
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, via Mancinelli 7, Milano 20131, Italy
| | - Francesco Cellesi
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, via Mancinelli 7, Milano 20131, Italy
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Akbarzadehlaleh P, Mirzaei M, Mashahdi-Keshtiban M, Heidari HR. The Effect of Length and Structure of Attached Polyethylene Glycol Chain on Hydrodynamic Radius, and Separation of PEGylated Human Serum Albumin by Chromatography. Adv Pharm Bull 2021; 11:728-738. [PMID: 34888220 PMCID: PMC8642789 DOI: 10.34172/apb.2021.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/28/2020] [Accepted: 08/05/2020] [Indexed: 11/09/2022] Open
Abstract
Purpose: This study focuses on the effect of length and structure of attached polyethylene glycol (PEG) chain on hydrodynamic radius (Rh ) and chromatographic retention of PEGylated protein. To this aim human serum albumin (HSA) as a standard protein was PEGylated site specifically with mPEG-maleimide. Methods: Separated PEG_HSA fractions were analyzed by size exclusion and anion exchange chromatography (AExC). The purity of fractions and the relative mobility of PEGylated and native proteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Hydrodynamic radius was determined based on the retention time of fractions on size exclusion chromatography (SEC), and also according to the previously reported equations. Results: A linear relation was shown between the molecular weight of attached PEG and Rh of PEGylated HSA. No significant difference between Rh of proteins modified with linear and branched PEG was shown. In SDS-PAGE, the delaying effect of branched PEG on movement of PEGylated protein was higher than that of linear PEG. Conclusion: As PEGylated HSA and dimer HSA have almost the same size and in SEC they elute at very close retention times, so in this case ion exchange chromatography (IExC) is more effective than SEC in separation of PEGylated HSA. Branched PEG- HSA showed earlier elution on anion exchange chromatography compared to linear PEG-HSA, that this can explain the different shielding effect of various structures of attached PEGs. The smaller size of PEGylated HSA in compare to the sum of the hydrodynamic radiuses of native HSA and attached PEG could be as a result of shielded attachment of polymer around protein.
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Affiliation(s)
- Parvin Akbarzadehlaleh
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mona Mirzaei
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahdiyeh Mashahdi-Keshtiban
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamid Reza Heidari
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
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4
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Site-Specific Cross-Linking of Galectin-1 Homodimers via Poly(ethylene glycol) Bismaleimide. Cell Mol Bioeng 2021; 14:523-534. [PMID: 34777608 DOI: 10.1007/s12195-021-00681-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 05/26/2021] [Indexed: 12/25/2022] Open
Abstract
Introduction The promise of the natural immunoregulator, Galectin-1 (Gal1), as an immunomodulatory therapeutic is challenged by its unstable homodimeric conformation. Previously, a Gal1 homodimer stabilized via covalent poly(ethylene glycol) diacrylate (PEGDA) cross-linking demonstrated higher activity relative to the non-covalent homodimer. Methods Here, we report Gal1 homodimers formed using an alternative thiol-Michael addition linker chemistry. Results Poly(ethylene glycol) bismaleimide (PEGbisMal) reacted with Gal1 at multiple sites with greater efficiency than PEGDA. However, multiple PEGbisMal molecules were conjugated to Gal1 C130, a Gal1 mutant with one surface cysteine (cys-130) and two cysteines thought to be buried in the solvent-inaccessible protein core (cys-42 and cys-60). Site-directed mutagenesis demonstrated that cys-60 was the site at which additional PEGbisMal molecules were conjugated onto Gal1 C130. Compared to WT-Gal1, Gal1 C130 had low activity for inducing Jurkat T cell death, characterized by phosphatidylserine exposure and membrane permeability. PEG cross-linking could restore the function of Gal1 C130, such that at high concentrations Gal1 C130 cross-linked by PEGbisMal had higher activity than both WT-Gal1 and Gal1 C130 cross-linked by PEGDA. Mutating cys-42 and cys-60 to serines in Gal1 C130 did not affect the cell death signaling activity of the Gal1 C130 homodimer cross-linked by PEGbisMal. PEGylated Gal1 C130 variants also eliminated the need for a reducing agent, such as dithiothreitol, which is required to maintain WT-Gal1 signaling activity. Conclusion Collectively, these data demonstrate that thiol-Michael addition bioconjugation leads to a PEG-cross-linked Gal1 homodimer with improved extracellular signaling activity that does not require a reducing environment to be functional.
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5
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Tully M, Hauptstein N, Licha K, Meinel L, Lühmann T, Haag R. Linear Polyglycerol for N-terminal-selective Modification of Interleukin-4. J Pharm Sci 2021; 111:1642-1651. [PMID: 34728175 DOI: 10.1016/j.xphs.2021.10.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 01/13/2023]
Abstract
Polymer conjugation to biologics is of key interest to the pharmaceutical industry for the development of potent and long acting biotherapeutics, with poly(ethylene glycol) (PEG) being the gold standard. Within the last years, unwanted PEG-related side effects (immunological reactions, antibody formation) arose, therefore creating several attempts to establish alternative polymers with similar potential to PEG. In this article, we synthesized N-terminal bioconjugates of the potential therapeutic human interleukin-4 (hIL-4 WT) with linear polyglycerol (LPG) of 10 and 40 kDa and compared it with its PEG analogs of same nominal weights. Polyglycerol is a highly hydrophilic polymer with good biocompatibility and therefore represents an alternative polymer to PEG. Both polymer types resulted in similar conjugation yields, comparable hydrodynamic sizes and an unaltered secondary structure of the protein after modification. LPG- and PEG-bioconjugates remained stable in human plasma, whereas binding to human serum albumin (HSA) decreased after polymer modification. Furthermore, only minor differences in bioactivity were observed between LPG- and PEG-bioconjugates of same nominal weights. The presented findings are promising for future pharmacokinetic evaluation of hIL-4-polymer bioconjugates.
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Affiliation(s)
- Michael Tully
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin Germany
| | - Niklas Hauptstein
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg Germany
| | - Kai Licha
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin Germany
| | - Lorenz Meinel
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg Germany; Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), 97080 Würzburg, Germany
| | - Tessa Lühmann
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg Germany
| | - Rainer Haag
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin Germany.
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6
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Tully M, Wedepohl S, Kutifa D, Weise C, Licha K, Schirner M, Haag R. Prolonged activity of exenatide: Detailed comparison of Site-specific linear polyglycerol- and poly(ethylene glycol)-conjugates. Eur J Pharm Biopharm 2021; 164:105-113. [PMID: 33957224 DOI: 10.1016/j.ejpb.2021.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/15/2021] [Accepted: 04/26/2021] [Indexed: 12/23/2022]
Abstract
Exenatide is a small therapeutic peptide being currently used in clinic for the treatment of diabetes mellitus type II, however, displaying a short blood circulation time which makes two daily injections necessary. Covalent polymer modification of a protein is a well-known approach to overcome this limitation, resulting in steric shielding, an increased size and therefore a longer circulation half-life. In this study, we employed site-selective C-terminal polymer ligation of exenatide via copper-catalyzed azide-alkyne-cycloaddition (CuAAC) to yield 1:1-conjugates of either poly(ethylene glycol) (PEG) or linear polyglycerol (LPG) of different molecular weights. Our goal was to compare the impact of the two polymers on size, structure and activity of exenatide on the in vitro and in vivo level. Both polymers did not alter the secondary structure of exenatide and expectedly increased its hydrodynamic size, where the LPG-versions of exenatide showed slightly smaller values than their PEG-analogs of same molecular weight. Upon conjugation, GLP-1 receptor activation was diminished, however, still enabled maximum receptor response at slightly higher concentrations. Exenatide modified with a 40 kDa LPG (Ex-40-LPG) showed significant reduction of the blood glucose level in diabetic mice for up to 72 h, which was comparable to its PEG-analog, but 9-fold longer than native exenatide (8 h).
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Affiliation(s)
- Michael Tully
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Stefanie Wedepohl
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Daniel Kutifa
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Christoph Weise
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Kai Licha
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Michael Schirner
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Rainer Haag
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany.
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7
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Tully M, Dimde M, Weise C, Pouyan P, Licha K, Schirner M, Haag R. Polyglycerol for Half-Life Extension of Proteins-Alternative to PEGylation? Biomacromolecules 2021; 22:1406-1416. [PMID: 33792290 DOI: 10.1021/acs.biomac.0c01627] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since several decades, PEGylation is known to be the clinical standard to enhance pharmacokinetics of biotherapeutics. In this study, we introduce polyglycerol (PG) of different lengths and architectures (linear and hyperbranched) as an alternative polymer platform to poly(ethylene glycol) (PEG) for half-life extension (HLE). We designed site-selective N-terminally modified PG-protein conjugates of the therapeutic protein anakinra (IL-1ra, Kineret) and compared them systematically with PEG analogues of similar molecular weights. Linear PG and PEG conjugates showed comparable hydrodynamic sizes and retained their secondary structure, whereas binding affinity to IL-1 receptor 1 decreased with increasing polymer length, yet remained in the low nanomolar range for all conjugates. The terminal half-life of a 40 kDa linear PG-modified anakinra was extended 4-fold compared to the unmodified protein, close to its PEG analogue. Our results demonstrate similar performances of PEG- and PG-anakinra conjugates and therefore highlight the outstanding potential of polyglycerol as a PEG alternative for half-life extension of biotherapeutics.
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Affiliation(s)
- Michael Tully
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Mathias Dimde
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Christoph Weise
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Paria Pouyan
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Kai Licha
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Michael Schirner
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
| | - Rainer Haag
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany
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8
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Li H, Huo J, Sun D, Guo Y, Jiang L, Zhang H, Shi X, Zhao Z, Zhou J, Hu C, Zhang C. Determination of PEGylation homogeneity of polyethylene glycol-modified canine uricase. Electrophoresis 2020; 42:693-699. [PMID: 33247595 DOI: 10.1002/elps.202000268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 10/13/2020] [Accepted: 11/17/2020] [Indexed: 12/17/2022]
Abstract
Polyethylene glycol-modified canine uricase (PEG-UHC) was prepared by modifying the ε-amino group of lysine residues on the canine uricase (UHC) protein to near-saturation with 5 kDa monomethoxyl-polyethylene glycol succinimide (mPEG-SPA-5k). In order to accurately determine the PEGylation uniformity of PEG-UHC, CZE, 3-8% gradient gel SDS-PAGE, and imaging CIEF (iCIEF) analyses were compared. CZE could not effectively separate PEG-UHC proteins with different degrees of modification, 3-8% gradient gel SDS-PAGE could separate PEG-UHC into seven gel bands; however, most of the gel bands were smeared or blurred, and the separation of PEG-UHC samples by iCIEF was significantly better than that by 3-8% gradient gel SDS-PAGE. Under denatured conditions, iCIEF separated 12 pI peaks, and could also accurately quantify the relative monomer PEG-UHC content. More than 85% of the total monomeric PEG-UHC was conjugated with 7-12 PEG molecules; of this 85%, approximately 40% was conjugated with 9-10 PEG molecules. These results demonstrated that iCIEF exhibits good potential for determining the PEGylation homogeneity of PEGylated protein drugs.
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Affiliation(s)
- Haigang Li
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - JingJing Huo
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - Dan Sun
- Rizhao Institute of Scientific and Technological Information, Shandong, P.R. China
| | - Yong Guo
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - Liang Jiang
- Renrui Biotechnology Inc., Shandong, P.R. China
| | - Haijuan Zhang
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - Xiaowei Shi
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - Zhilong Zhao
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - Jinchuan Zhou
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China
| | - Chunlan Hu
- Fagen Biomedical Inc., Chongqing, P.R. China
| | - Chun Zhang
- College of Pharmacy, Linyi University, Linyi, Shandong, 276000, P.R. China.,Renrui Biotechnology Inc., Shandong, P.R. China
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9
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10
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Nakamura H, Anraku M, Oda-Ueda N, Ueda T, Ohkuri T. C-Terminal Cysteine PEGylation of Adalimumab Fab with an Engineered Interchain SS Bond. Biol Pharm Bull 2020; 43:418-423. [PMID: 31866612 DOI: 10.1248/bpb.b19-00612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Conjugation with polyethylene glycol (PEG) is performed to increase serum half-life of the Fab for clinical applications. However, current designs for recombinant Fab only allow PEGylation at the interchain SS bond (disulfide bond) at the C-terminal end of the heavy chain and light chain of the Fab, which the decrease of thermostability occurred by partial reduction of the interchain SS bond. An adalimumab Fab mutant with a novel interchain SS bond (CH1 : C177-CL : C160) and one cysteine at the C-terminal end (mutSS FabSH) was designed to maintain Fab thermostability and for site-specific PEGylation. MutSS FabSH was expressed in Pichia pastoris and purified mutSS FabSH was conjugated with 20-kDa PEG targeted at the free cysteine. Based on enzyme-linked immunosorbent assay (ELISA), PEGylation did not affect the binding capacity of the mutSS FabSH. To confirm the influence of PEGylation on the pharmacokinetic behavior of the Fab, PEGylated mutSS FabSH was administered to rats via tail vein injection. Analysis of the mean serum concentration of the PEGylated mutSS FabSH versus time through ELISA indicated an increase in half-life compared to that of non-PEGylated wild-type Fab. Consequently, we have successfully demonstrated that a Fab mutant with a novel interchain SS bond and one free cysteine at the C-terminal end can be PEGylated without changes in functionality. This design can potentially be used as a platform for modification of other recombinant Fabs.
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Affiliation(s)
| | | | | | - Tadashi Ueda
- Graduate School of Pharmaceutical Sciences, Kyushu University
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11
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Dynamic membrane topology in an unassembled membrane protein. Nat Chem Biol 2019; 15:945-948. [DOI: 10.1038/s41589-019-0356-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/31/2019] [Indexed: 11/08/2022]
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12
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Vega IE, Umstead A, Kanaan NM. EFhd2 Affects Tau Liquid-Liquid Phase Separation. Front Neurosci 2019; 13:845. [PMID: 31456657 PMCID: PMC6700279 DOI: 10.3389/fnins.2019.00845] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 07/30/2019] [Indexed: 12/17/2022] Open
Abstract
The transition of tau proteins from its soluble physiological conformation to the pathological aggregate forms found in Alzheimer's disease and related dementias, is poorly understood. Therefore, understanding the process that modulates the formation of toxic tau oligomers and their conversion to putative neuroprotective neurofibrillary tangles will lead to better therapeutic strategies. We previously identified that EFhd2 is associated with aggregated tau species in AD brains and the coiled-coil domain in EFhd2 mediates the interaction with tau. To further characterize the association between EFhd2 and tau, we examined whether EFhd2 could affect the liquid-liquid phase separation properties of tau under molecular crowding conditions. We demonstrate that EFhd2 alters tau liquid phase behavior in a calcium and coiled-coil domain dependent manner. Co-incubation of EFhd2 and tau in the absence of calcium leads to the formation of solid-like structures containing both proteins, while in the presence of calcium these two proteins phase separate together into liquid droplets. EFhd2's coiled-coil domain is necessary to alter tau's liquid phase separation, indicating that protein-protein interaction is required. The results demonstrate that EFhd2 affects the liquid-liquid phase separation of tau proteins in vitro, suggesting that EFhd2 modulates the structural dynamics of tau proteins.
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Affiliation(s)
- Irving E Vega
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, Grand Rapids, MI, United States.,Department of Neurology, University of Michigan, Ann Arbor, MI, United States
| | - Andrew Umstead
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Grand Rapids, MI, United States
| | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, Grand Rapids, MI, United States.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, United States
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13
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Guo L, Xu B, Zhou D, Chang G, Fu Y, Liu L, Luo Y. Biophysical and biological characterization of PEGylated recombinant human endostatin. Clin Exp Pharmacol Physiol 2019; 46:920-927. [PMID: 31278773 DOI: 10.1111/1440-1681.13134] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/24/2019] [Accepted: 07/01/2019] [Indexed: 01/17/2023]
Abstract
Recombinant human endostatin (MES), showing potent inhibition on angiogenesis and tumour growth, has great potential as a therapeutic agent for tumours. The aim of this study was to evaluate the biophysical and biological characterization of PEGylated recombinant human endostatin (M2 ES). Recombinant human endostatin was mono-PEGylated by conjugation with methoxy polyethylene glycol aldehyde (mPEG-ALD), and the modification site was identified by digested peptide mapping and matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The purity was assessed by SDS-PAGE, high-performance liquid chromatography (HPLC), and capillary zone electrophoresis. The physicochemical property was analyzed through fluorescence spectroscopy, and circular dichroism. The bioactivity and anti-tumour efficacy of M2 ES were evaluated using an in vitro endothelial cell migration model and a null-mouse xenograft model of a prostatic cancer, respectively. M2 ES molecules contain a single 20 kDa mPEG-ALD molecule conjugated at the N-terminal portion of MES. The purity of M2 ES was greater than 98%. The physicochemical analysis demonstrated that PEGylation does not change the secondary and tertiary structure of MES. Notably, M2 ES retards endothelial cell migration and tumour growth when compared to control group. These biophysical and biological characterization study data contribute to the initiation of the ongoing clinical study.
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Affiliation(s)
- Lifang Guo
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Benshan Xu
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Daifu Zhou
- National Engineering Laboratory for Anti-tumour Protein Therapeutics, Tsinghua University, Beijing, China
| | - Guodong Chang
- National Engineering Laboratory for Anti-tumour Protein Therapeutics, Tsinghua University, Beijing, China
| | - Yan Fu
- National Engineering Laboratory for Anti-tumour Protein Therapeutics, Tsinghua University, Beijing, China.,Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing, China.,Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lihong Liu
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Yongzhang Luo
- National Engineering Laboratory for Anti-tumour Protein Therapeutics, Tsinghua University, Beijing, China.,Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing, China.,Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing, China
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14
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Han Y, Zang K, Liu C, Li Y, Ma Q. The putative siderophore-interacting protein from Vibrio anguillarum: protein production, analysis, crystallization and X-ray crystallographic studies. Acta Crystallogr F Struct Biol Commun 2018; 74:283-287. [PMID: 29717995 PMCID: PMC5931140 DOI: 10.1107/s2053230x18005125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/29/2018] [Indexed: 11/10/2022] Open
Abstract
Siderophore-interacting proteins (SIPs) play an important role in iron acquisition in many bacteria. SIPs release iron from the internalized ferric siderophore complex by reducing ferric iron to ferrous iron, but how the iron is reduced is not well understood. Here, a sip gene was identified in the genome of Vibrio anguillarum 775. To further understand the catalytic mechanism of the protein, the SIP was overexpressed in Escherichia coli Rosetta (DE3) cells, purified and crystallized for X-ray diffraction analysis. The crystal diffracted to 1.113 Å resolution and belonged to space group P21, with unit-cell parameters a = 64.63, b = 58.47, c = 70.65 Å, β = 114.19°.
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Affiliation(s)
- Yu Han
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, People’s Republic of China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Kun Zang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, People’s Republic of China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Changshui Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, People’s Republic of China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, People’s Republic of China
| | - Yingjie Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, People’s Republic of China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, People’s Republic of China
| | - Qingjun Ma
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, People’s Republic of China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, People’s Republic of China
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15
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White CJ, Bode JW. PEGylation and Dimerization of Expressed Proteins under Near Equimolar Conditions with Potassium 2-Pyridyl Acyltrifluoroborates. ACS CENTRAL SCIENCE 2018; 4:197-206. [PMID: 29532019 PMCID: PMC5833003 DOI: 10.1021/acscentsci.7b00432] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Indexed: 05/27/2023]
Abstract
The covalent conjugation of large, functionalized molecules remains a frontier in synthetic chemistry, as it requires rapid, chemoselective reactions. The potassium acyltrifluoroborate (KAT)-hydroxylamine amide-forming ligation shows promise for conjugations of biomolecules under aqueous, acidic conditions, but the variants reported to date are not suited to ligations at micromolar concentrations. We now report that 2-pyridyl KATs display significantly enhanced ligation kinetics over their aryl counterparts. Following their facile, one-step incorporation onto the termini of polyethylene glycol (PEG) chains, we show that 2-pyridyl KATs can be applied to the construction of protein-polymer conjugates in excellent (>95%) yield. Four distinct expressed, folded proteins equipped with a hydroxylamine could be PEGylated with 2-20 kDa 2-pyridyl mPEG KATs in high yield and with near-equimolar amounts of coupling partners. Furthermore, the use of a bis 2-pyridyl PEG KAT enables the covalent homodimerization of proteins with good conversion. The 2-pyridyl KAT ligation offers an effective alternative to conventional protein-polymer conjugation by operating under aqueous acidic conditions well suited for the handling of folded proteins.
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Affiliation(s)
- Christopher J. White
- Laboratorium für Organische Chemie,
Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - Jeffrey W. Bode
- Laboratorium für Organische Chemie,
Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
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16
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Abstract
The topologies of α-helical membrane proteins are generally thought to be determined during their cotranslational insertion into the membrane. It is typically assumed that membrane topologies remain static after this process has ended. Recent findings, however, question this static view by suggesting that some parts of, or even the whole protein, can reorient in the membrane on a biologically relevant time scale. Here, we focus on antiparallel homo- or heterodimeric small multidrug resistance proteins and examine whether the individual monomers can undergo reversible topological inversion (flip flop) in the membrane until they are trapped in a fixed orientation by dimerization. By perturbing dimerization using various means, we show that the membrane orientation of a monomer is unaffected by the presence or absence of its dimerization partner. Thus, membrane-inserted monomers attain their final orientations independently of dimerization, suggesting that wholesale topological inversion is an unlikely event in vivo.
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17
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Quantification of PEGylated proteases with varying degree of conjugation in mixtures: An analytical protocol combining protein precipitation and capillary gel electrophoresis. J Chromatogr A 2016; 1462:153-64. [DOI: 10.1016/j.chroma.2016.07.078] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 11/20/2022]
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18
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Gecchele E, Schillberg S, Merlin M, Pezzotti M, Avesani L. A downstream process allowing the efficient isolation of a recombinant amphiphilic protein from tobacco leaves. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 960:34-42. [PMID: 24786219 DOI: 10.1016/j.jchromb.2014.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/26/2014] [Accepted: 04/02/2014] [Indexed: 10/25/2022]
Abstract
The 65-kDa isoform of human glutamic acid decarboxylase (hGAD65) is a major autoantigen in autoimmune diabetes. The heterologous production of hGAD65 for diagnostic and therapeutic applications is hampered by low upstream productivity and the absence of a robust and efficient downstream process for product isolation. A tobacco-based platform has been developed for the production of an enzymatically-inactive form of the protein (hGAD65mut), but standard downstream processing strategies for plant-derived recombinant proteins cannot be used in this case because the product is amphiphilic. We therefore evaluated different extraction buffers and an aqueous micellar two-phase system (AMTPS) to optimize the isolation and purification of hGAD65mut from plants. We identified the extraction conditions offering the greatest selectivity for hGAD65mut over native tobacco proteins using a complex experimental design approach. Under our optimized conditions, the most efficient initial extraction and partial purification strategy achieved an overall hGAD65mut yield of 92.5% with a purification factor of 12.3 and a concentration factor of 23.8. The process also removed a significant quantity of phenols, which are major contaminants present in tobacco tissue. This is the first report describing the use of AMTPS for the partial purification of an amphiphilic recombinant protein from plant tissues and our findings could also provide a working model for the initial recovery and partial purification of hydrophobic recombinant proteins from transgenic tobacco plants.
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Affiliation(s)
- Elisa Gecchele
- University of Verona, Department of Biotechnology, Verona, Italy
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Matilde Merlin
- University of Verona, Department of Biotechnology, Verona, Italy
| | - Mario Pezzotti
- University of Verona, Department of Biotechnology, Verona, Italy
| | - Linda Avesani
- University of Verona, Department of Biotechnology, Verona, Italy.
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19
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Chatterjea SM, Panda K. Development of a multiple-bile-ion-sensing membrane electrode. Anal Biochem 2013; 441:218-24. [PMID: 23871999 DOI: 10.1016/j.ab.2013.06.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/21/2013] [Accepted: 06/28/2013] [Indexed: 01/10/2023]
Abstract
A multiple-bile-ion-sensing polyvinyl chloride-based membrane electrode capable of monitoring any of the three common bile ions in humans, namely, cholate, deoxycholate, and chenodeoxycholate, was developed and characterized. Compared to single-bile-ion-sensing electrodes, it showed a sub-Nernstian response. All other electrode properties were, however, similar, making this a successful replacement for three individual electrodes. With appropriate conditioning, this electrode could repeatedly change selectivity without losing membrane activity. It was reproducible, was stable for 5 months, had low response time, and could be used to measure critical micelle concentrations. The lower limit of detection was 10 nM. Selectivity coefficients for various anions with respect to bile ions more or less followed the Hoffmeister series. Plots of R ((Nernst equivalent of slope in the presence of primary ion and a fixed amount of interfering ion)/(slope in the presence of only the primary ion)) vs square root of ionic strength for an interfering ion were linear. One major application of this electrode is its use in kinetics. We have tested its ability to monitor continuously changing bile ion concentrations during their interactions with a biocompatible polymer, polyethylene glycol (6000), and determined rate constants.
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Affiliation(s)
- Sudeshna M Chatterjea
- Department of Biotechnology and Dr. B.C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata 700019, West Bengal, India.
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20
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Quantification of thiols and disulfides. Biochim Biophys Acta Gen Subj 2013; 1840:838-46. [PMID: 23567800 DOI: 10.1016/j.bbagen.2013.03.031] [Citation(s) in RCA: 238] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 11/23/2022]
Abstract
BACKGROUND Disulfide bond formation is a key posttranslational modification, with implications for structure, function and stability of numerous proteins. While disulfide bond formation is a necessary and essential process for many proteins, it is deleterious and disruptive for others. Cells go to great lengths to regulate thiol-disulfide bond homeostasis, typically with several, apparently redundant, systems working in parallel. Dissecting the extent of oxidation and reduction of disulfides is an ongoing challenge due, in part, to the facility of thiol/disulfide exchange reactions. SCOPE OF REVIEW In the present account, we briefly survey the toolbox available to the experimentalist for the chemical determination of thiols and disulfides. We have chosen to focus on the key chemical aspects of current methodology, together with identifying potential difficulties inherent in their experimental implementation. MAJOR CONCLUSIONS While many reagents have been described for the measurement and manipulation of the redox status of thiols and disulfides, a number of these methods remain underutilized. The ability to effectively quantify changes in redox conditions in living cells presents a continuing challenge. GENERAL SIGNIFICANCE Many unresolved questions in the metabolic interconversion of thiols and disulfides remain. For example, while pool sizes of redox pairs and their intracellular distribution are being uncovered, very little is known about the flux in thiol-disulfide exchange pathways. New tools are needed to address this important aspect of cellular metabolism. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.
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21
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The molar hydrodynamic volume changes of factor VIIa due to GlycoPEGylation. J Pharm Biomed Anal 2011; 55:597-602. [PMID: 21429688 DOI: 10.1016/j.jpba.2011.02.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 02/22/2011] [Accepted: 02/23/2011] [Indexed: 11/23/2022]
Abstract
The effects of GlycoPEGylation on the molar hydrodynamic volume of recombinant human rFVIIa were investigated using rFVIIa and two GlycoPEGylated recombinant human FVIIa derivatives, a linear 10kDa PEG and a branched 40kDa PEG, respectively. Molar hydrodynamic volumes were determined by capillary viscometry and mass spectrometry. The intrinsic viscosities of rFVIIa, its two GlycoPEGylated compounds, and of linear 8kDa, 10kDa, 20kDa and branched 40kDa PEG polymers were determined. The measured intrinsic viscosity of rFVIIa is 6.0mL/g, while the intrinsic viscosities of 10kDa PEG-rFVIIa and 40kDa PEG-rFVIIa are 29.5mL/g and 79.0mL/g, respectively. The intrinsic viscosities of the linear PEG polymers are 20, 22.6 and 41.4mL/g for 8, 10, and 20kDa, respectively, and 61.1mL/g for the branched 40kDa PEG. From the results of the intrinsic viscosity and MALDI-TOF measurements it is evident, that the molar hydrodynamic volume of the conjugated protein is not just an addition of the molar hydrodynamic volume of the PEG and the protein. The molar hydrodynamic volume of the GlycoPEGylated protein is larger than the volume of its composites. These results suggest that both the linear and the branched PEG are not wrapped around the surface of rFVIIa but are chains that are significantly stretched out when attached to the protein.
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22
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23
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Reichel C, Abzieher F, Geisendorfer T. SARCOSYL-PAGE: a new method for the detection of MIRCERA- and EPO-doping in blood. Drug Test Anal 2010; 1:494-504. [PMID: 20355164 DOI: 10.1002/dta.97] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The detection of doping with MIRCERA (the brand name for Continuous Erythropoietin Receptor Activator, or CERA) is hampered by the limited excretion of the rather large molecule (approximately 60 kDa) in urine. Blood (serum, plasma) in combination with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) appears to be the ideal matrix for detecting all forms of doping with erythropoiesis-stimulating agents (ESAs) because the apparent molecular masses of ESAs are different from the mass of human serum erythropoietin (shEPO). While SDS-PAGE has proven the most sensitive method for the detection of doping with Dynepo, the sensitivity of SDS-PAGE for MIRCERA is drastically decreased. By exchanging the SDS for SARCOSYL (SAR) in the sample and running buffers the sensitivity problem was solved. SARCOSYL, a methyl glycine-based anionic surfactant, is only binding to the protein-part of MIRCERA but not to its polyethylene glycol (PEG)-chain, while SDS binds to both parts. In consequence, the monoclonal anti-EPO antibody (clone AE7A5) no longer interacts with the fully SDS-solubilized MIRCERA molecules. Only those molecules that contain SDS bound to the protein-chain are detected. Due to the inability of SARCOSYL to solubilize PEG-molecules, MIRCERA can be detected on SARCOSYL-PAGE with the same sensitivity as non-PEGylated epoetins. In a typical SAR-PAGE experiment, 200 microL of serum are used, which allows the direct detection of MIRCERA, recombinant epoetins (such as NeoRecormon, Dynepo, NESP), and shEPO in a single experiment and with high (i.e. femtogram) sensitivity.
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Affiliation(s)
- Christian Reichel
- Doping Control Laboratory, AIT Seibersdorf Laboratories, Seibersdorf, Austria.
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24
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Tong Y, Zhong K, Tian H, Gao X, Xu X, Yin X, Yao W. Characterization of a monoPEG20000-Endostar. Int J Biol Macromol 2010; 46:331-6. [PMID: 20122957 DOI: 10.1016/j.ijbiomac.2010.01.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 01/20/2010] [Accepted: 01/21/2010] [Indexed: 01/16/2023]
Abstract
In this study, we investigated the PEG attachment site of mono-PEGylated Endostar, a modified recombinant human endostatin approved in China for lung cancer. N-terminal site-directed mono-PEGylation of Endostar was accomplished using mPEG-propionaldehyde derivatives (Mw=20 kDa) under slightly acidic pH conditions (pH 5.5). One-step cation exchange chromatography was used to purify the mono-PEGylated Endostar. Following tryptic digestion, the peptide fragment containing PEG was separated by SDS-PAGE. Barium iodide staining and Western blotting were used to detect the PEG moiety and the N-terminus of Endostar, respectively. The peptide fragment stained by barium iodide showed a positive response to anti-(His) 6 mAb, demonstrating that PEG was located at the N-terminus of Endostar. LC/MS was applied to verify the occurrence of mono-PEGylation at the N-terminus of Endostar.
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Affiliation(s)
- Yue Tong
- Department of Biochemistry, China Pharmaceutical University, Nanjing 210009, China
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25
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Zheng C, Zheng CY, Ma G, Su Z. Native PAGE eliminates the problem of PEG–SDS interaction in SDS-PAGE and provides an alternative to HPLC in characterization of protein PEGylation. Electrophoresis 2007; 28:2801-7. [PMID: 17702059 DOI: 10.1002/elps.200600807] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PEGylation of proteins has become an increasingly important technology in recent years. However, determination and characterization of the PEGylation products are problematic especially for the reaction mixture containing various modified proteins, unreacted PEG, and unmodified protein. A comparative study was carried out with two HPLC methods and two electrophoresis methods for characterization of the reaction mixture in PEGylation of HSA with PEG 5000, 10000, and 20000. RP-HPLC fails to give the correct information about the reaction of PEG 20000. Size-exclusion HPLC (SE-HPLC) produced very poor resolution on the PEG 5000 reaction. SDS-PAGE can run multiple samples of all PEGylation but the bands were smeared or broadened probably due to the interaction between PEG and SDS. On the other hand, native PAGE eliminates the problem of PEG-SDS interaction and provides better resolutions for all samples. Various PEGylated products and unmodified protein migrate differentially in native PAGE under nondenatured conditions. The results demonstrated that native PAGE could be a good alternative to HPLC and SDS-PAGE for the analysis of PEG-protein conjugates especially for characterization of the PEGylation mixture.
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Affiliation(s)
- Chunyang Zheng
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China
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26
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Bakke CK, Jungbauer LM, Cavagnero S. In vitro expression and characterization of native apomyoglobin under low molecular crowding conditions. Protein Expr Purif 2006; 45:381-92. [PMID: 16169747 DOI: 10.1016/j.pep.2005.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 07/29/2005] [Accepted: 08/01/2005] [Indexed: 10/25/2022]
Abstract
The labile nature of membranes and organelles poses serious challenges to in situ biomolecule characterization in intact cells. Cell-free in vitro systems provide an alternative promising medium for the expression and characterization of protein conformation and function in a biochemical context that bears several similarities to the cellular environment. In addition, cell-free transcription-translation has recently emerged as a convenient method for protein selective isotope labeling, providing significant advantages for detailed NMR analysis. We report the cell-free expression of the model protein apomyoglobin (apoMb) in an Escherichia coli cell-free system and the effect of polyethylene glycol (PEG) on the expression yields. In contrast with in vivo protein production under control of the strong T7 promoter, apoMb is expressed in vitro in 100% soluble form. In-gel tryptic digestion followed by mass spectrometry were performed to confirm the protein identity. In order to probe the conformation of the newly expressed protein and investigate the feasibility of in situ structural analysis, high resolution protein characterization was carried out by 2D NMR spectroscopy. In vitro apoMb expression in a PEG-free environment is a convenient method for the production of soluble native-like protein under conditions amenable to selective isotopic labeling. Yields can be easily scaled-up by dialysis-assisted cell-free expression.
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Affiliation(s)
- Courtney K Bakke
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
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27
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Barker TH, Fuller GM, Klinger MM, Feldman DS, Hagood JS. Modification of fibrinogen with poly(ethylene glycol) and its effects on fibrin clot characteristics. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001; 56:529-35. [PMID: 11400130 DOI: 10.1002/1097-4636(20010915)56:4<529::aid-jbm1124>3.0.co;2-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The suitability of existing topical fibrin glue preparations for tissue sealing or local drug delivery applications is greatly limited by their poor mechanical properties and the limited capacity of fibrinogen (Fgn) to actively bind growth factors or other therapeutic agents. Poly(ethylene glycol) (PEG) offers potential solutions to these problems by providing a mechanism for increasing the number of crosslinks between adjacent fibrin monomer molecules or for covalently crosslinking Fgn to therapeutic agents. The feasibility of this approach requires the full biological activity, or clottability, of PE glycolated Fgn. This study characterizes the clot characteristics of Fgn modified to varying degrees with monofunctional succinimidyl propionate PEG (5000 Da). The data indicate that, although thrombin clotting times are significantly altered, Fgn maintains 90% of its capacity to clot upon the addition of up to 5 PEG/Fgn. Further derivatization significantly decreases the Fgn clottability. The addition of up to 5 PEG/Fgn has little, if any, effect on the kinetics of degradation by plasmin. The results suggest that limited modification of Fgn with lysine-reactive PEG allows therapeutic enhancement of fibrin glues.
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Affiliation(s)
- T H Barker
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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28
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Barker TH, Klinger MM, Feldman DS, Fuller GM, Hagood JS. Spectrophotometric analysis for determining the average number of poly(ethylene) glycol molecules on PEGylated proteins utilizing a protein digestion step. Anal Biochem 2001; 290:382-5. [PMID: 11237345 DOI: 10.1006/abio.2001.4987] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- T H Barker
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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29
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Determination of surfactant concentration using micellar enhanced fluorescence and flow injection titration. Talanta 2000; 50:1283-9. [DOI: 10.1016/s0039-9140(99)00238-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/1999] [Revised: 07/29/1999] [Accepted: 08/03/1999] [Indexed: 11/23/2022]
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30
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Kigawa T, Yabuki T, Yoshida Y, Tsutsui M, Ito Y, Shibata T, Yokoyama S. Cell-free production and stable-isotope labeling of milligram quantities of proteins. FEBS Lett 1999; 442:15-9. [PMID: 9923595 DOI: 10.1016/s0014-5793(98)01620-2] [Citation(s) in RCA: 361] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have improved the productivity of an Escherichia coli cell-free protein synthesis system. First, creatine phosphate and creatine kinase were used as the energy source regeneration system, and the other components of the reaction mixture were optimized. Second, the E. coli S30 cell extract was condensed by dialysis against a polyethylene glycol solution to increase the rate of synthesis. Third, during the protein synthesis, the reaction mixture was dialyzed against a low-molecular-weight substrate solution to prolong the reaction. Thus, the yield of chloramphenicol acetyltransferase was raised to 6 mg/ml of reaction mixture. Stable-isotope labeling of a protein with 13C/15N-labeled amino acids for NMR spectroscopy was achieved by this method.
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Affiliation(s)
- T Kigawa
- Cellular Signaling Laboratory, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, Japan
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31
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Takagi T. Capillary electrophoresis in presence of sodium dodecyl sulfate and a sieving medium. Electrophoresis 1997; 18:2239-42. [PMID: 9456038 DOI: 10.1002/elps.1150181214] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
For analysis of proteins in presence of sodium dodecyl sulfate (SDS), basic knowledge about their behavior in presence and absence of sieving medium is required. Capillary electrophoresis (CE) is particularly suitable for this purpose. Although various polymers are used as sieves in CE analysis in presence of SDS, attention must be paid to possible interaction between SDS and the polymer. For obtaining new insights polymers with defined molecular weight and distribution should be utilized.
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Affiliation(s)
- T Takagi
- Institute for Protein Research, Osaka University, Ibaraki, Japan.
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