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Gebretsadik H, Kahsay G, Adams E, Van Schepdael A. A comprehensive review of capillary electrophoresis-based techniques for erythropoietin isoforms analysis. J Chromatogr A 2023; 1708:464331. [PMID: 37660565 DOI: 10.1016/j.chroma.2023.464331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/18/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
Different CE techniques have been used to analyze erythropoietin. These techniques have been shown to be effective in differentiating and quantifying erythropoietin isoforms, including natural and recombinant origins. This review provides a comprehensive overview of various capillary electrophoresis-based techniques used for the analysis of erythropoietin isoforms. The importance of erythropoietin in clinical practice and the necessity for the accurate analysis of its isoforms are first discussed. Various techniques that have been used for erythropoietin isoform analysis are then described. The main body of the review focuses on the different capillary electrophoresis-based methods that have been developed for erythropoietin isoform analysis, including capillary zone electrophoresis and capillary isoelectric focusing. The advantages and drawbacks of each method as well as their applications are discussed. Suggestions into the future directions of the area are also described.
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Affiliation(s)
- Hailekiros Gebretsadik
- KU Leuven - University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium
| | - Getu Kahsay
- KU Leuven - University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium
| | - Erwin Adams
- KU Leuven - University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium
| | - Ann Van Schepdael
- KU Leuven - University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium.
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2
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Stutz H. Advances and applications of electromigration methods in the analysis of therapeutic and diagnostic recombinant proteins – A Review. J Pharm Biomed Anal 2022; 222:115089. [DOI: 10.1016/j.jpba.2022.115089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 11/29/2022]
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3
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Xiao X, Zhang Y, Wu J, Jia L. Poly(norepinephrine)-coated open tubular column for the separation of proteins and recombination human erythropoietin by capillary electrochromatography. J Sep Sci 2017; 40:4636-4644. [DOI: 10.1002/jssc.201700720] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/04/2017] [Accepted: 10/01/2017] [Indexed: 01/28/2023]
Affiliation(s)
- Xue Xiao
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science; College of Biophotonics; South China Normal University; Guangzhou China
| | - Yamin Zhang
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science; College of Biophotonics; South China Normal University; Guangzhou China
| | - Jia Wu
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science; College of Biophotonics; South China Normal University; Guangzhou China
| | - Li Jia
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science; College of Biophotonics; South China Normal University; Guangzhou China
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4
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Tu X, Muhammad P, Liu J, Ma Y, Wang S, Yin D, Liu Z. Molecularly Imprinted Polymer-Based Plasmonic Immunosandwich Assay for Fast and Ultrasensitive Determination of Trace Glycoproteins in Complex Samples. Anal Chem 2016; 88:12363-12370. [DOI: 10.1021/acs.analchem.6b03597] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Xueying Tu
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Pir Muhammad
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Jia Liu
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Yanyan Ma
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Shuangshou Wang
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Danyang Yin
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Zhen Liu
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
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Zhang L, Lawson K, Yeung B, Wypych J. Capillary Zone Electrophoresis Method for a Highly Glycosylated and Sialylated Recombinant Protein: Development, Characterization and Application for Process Development. Anal Chem 2014; 87:470-6. [DOI: 10.1021/ac504187v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Le Zhang
- Analytical
Sciences of Drug Substance Department, Amgen, Inc., Thousand Oaks, California 91320, United States
| | - Ken Lawson
- Analytical
Sciences of Drug Substance Department, Amgen, Inc., Thousand Oaks, California 91320, United States
| | - Bernice Yeung
- Analytical
Sciences of Drug Substance Department, Amgen, Inc., Thousand Oaks, California 91320, United States
| | - Jette Wypych
- Analytical
Sciences of Drug Substance Department, Amgen, Inc., Thousand Oaks, California 91320, United States
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6
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Pang N, Bai Y, Zhou Y, Yang X, Zhang Z, Nie H, Fu X, Liu H. Rapid and subnanomolar assay of recombinant human erythropoietin by capillary electrophoresis using NanoOrange precolumn labeling and laser-induced fluorescence detection. J Sep Sci 2014; 37:2233-8. [DOI: 10.1002/jssc.201400263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/07/2014] [Accepted: 05/12/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Nannan Pang
- School of Chemical and Biological Engineering; University of Science and Technology; Beijing P. R. China
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Yu Bai
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Yu Zhou
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Xia Yang
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Zhengxiang Zhang
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Honggang Nie
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Xiaofang Fu
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
| | - Huwei Liu
- Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Institute of Analytical Chemistry; College of Chemistry and Molecular Engineering, Peking University; Beijing P. R. China
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7
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Wang H, Dou P, Lü C, Liu Z. Immuno-magnetic beads-based extraction-capillary zone electrophoresis-deep UV laser-induced fluorescence analysis of erythropoietin. J Chromatogr A 2012; 1246:48-54. [DOI: 10.1016/j.chroma.2012.02.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/03/2012] [Accepted: 02/06/2012] [Indexed: 01/08/2023]
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8
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Girard M, Puerta A, Diez-Masa JC, de Frutos M. High resolution separation methods for the determination of intact human erythropoiesis stimulating agents. A review. Anal Chim Acta 2012; 713:7-22. [DOI: 10.1016/j.aca.2011.11.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 11/10/2011] [Accepted: 11/11/2011] [Indexed: 12/17/2022]
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9
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Protein glycosylation analysis with capillary-based electromigrative separation techniques. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s12566-010-0018-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
Erythropoietin (EPO), a glycoprotein hormone, stimulates the growth of red blood cells and as a consequence it increases tissue oxygenation. This performance enhancing effect is responsible for the ban of erythropioetin in sports since 1990. Especially its recombinant synthesis led to the abuse of this hormone, predominatly in endurance sports. The analytical differentiation of endogenously produced erythropoietin from its recombinant counterpart by using isoelectric focusing and double blotting is a milestone in the detection of doping with recombinant erythropoietin. However, various analogous of the initial recombinant products, not always easily detectable by the standard IEF-method, necessitate the development of analytical alternatives for the detection of EPO doping. The following chapter summarizes its mode of action, the various forms of recombinant erythropoietin, the main analytical procedures and strategies for the detection of EPO doping as well as a typical case report.
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Affiliation(s)
- Christian Reichel
- Austrian Research Centers GmbH - ARC, Doping Control Laboratory, A-2444, Seibersdorf, Austria.
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11
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Optimization and qualification of capillary zone electrophoresis method for glycoprotein isoform distribution of erythropoietin for quality control laboratory. J Pharm Biomed Anal 2009; 50:538-43. [DOI: 10.1016/j.jpba.2009.05.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/08/2009] [Accepted: 05/08/2009] [Indexed: 11/21/2022]
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12
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Alahmad Y, Thuy Tran N, Duboeuf J, Grégoire A, Rancé I, Taverna M. CZE for glycoform profiling and quality assessment of recombinant human interleukin-7. Electrophoresis 2009; 30:2347-54. [DOI: 10.1002/elps.200800789] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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13
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Dou P, Liu Z, He J, Xu JJ, Chen HY. Rapid and high-resolution glycoform profiling of recombinant human erythropoietin by capillary isoelectric focusing with whole column imaging detection. J Chromatogr A 2008; 1190:372-6. [DOI: 10.1016/j.chroma.2008.03.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 02/24/2008] [Accepted: 03/03/2008] [Indexed: 01/01/2023]
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14
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Technology Insight: detecting growth hormone abuse in athletes. ACTA ACUST UNITED AC 2007; 3:769-77. [DOI: 10.1038/ncpendmet0644] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 07/26/2007] [Indexed: 11/09/2022]
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15
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Lara-Quintanar P, Lacunza I, Sanz J, Diez-Masa JC, de Frutos M. Immunochromatographic removal of albumin in erythropoietin biopharmaceutical formulations for its analysis by capillary electrophoresis. J Chromatogr A 2007; 1153:227-34. [PMID: 16919660 DOI: 10.1016/j.chroma.2006.07.079] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 07/27/2006] [Accepted: 07/28/2006] [Indexed: 11/17/2022]
Abstract
Human serum albumin (HSA) is added to some pharmaceutical preparations as an excipient. This is the case for some of the commercial preparations of recombinant erythropoietin (rEPO). Differences in the number of the sialic acid moieties in the different rEPO glycoforms confer to these forms different net charges and different bioactivity. Knowledge of the isoforms present in each pharmaceutical product is then of interest. Differences in net charge of the rEPO forms make possible their separation by electrophoretical methods. However it has been observed in our laboratory that the amount of HSA usually present in these drug formulations interferes or even precludes separation of rEPO bands by capillary zone electrophoresis (CZE). In this work, an immunochromatographic method to remove HSA from rEPO biopharmaceutical formulations and a procedure to concentrate the sample that is needed to be performed prior to the analysis by CZE are developed. A home-made computer program to compare the percentage of correct assignments of electrophoretical bands provided by different migration parameters is used to study the effect of HSA remaining in samples on the accuracy of assignment of rEPO bands. When there exists a residual concentration of HSA in the sample (<2mg/ml) only the effective electrophoretic mobility is a reliable migration parameter to assign rEPO bands with a 100% of correct assignment. This parameter allows the correct assignment of bands of rEPO from pharmaceutical products formulated with HSA after immunochromatographic removal of HSA. Electrophoretical bands found in epoetin alpha, one of the commercial formulations of rEPO, are independent of the molecular mass of the excipients. The methodology used in this work for the analysis by CZE and the assignment of rEPO isoforms, as well as for the immunochromatographic HSA removal in the pharmaceutical products could be of high interest for the health authorities to control the quality of the product in marketing surveillance studies and for the quality control laboratories of the manufacturers.
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Affiliation(s)
- Pilar Lara-Quintanar
- Institute of Organic Chemistry (C.S.I.C.), Juan de la Cierva 3, 28006 Madrid, Spain
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16
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Azzazy HME, Mansour MMH. Rogue athletes and recombinant DNA technology: challenges for doping control. Analyst 2007; 132:951-7. [PMID: 17893796 DOI: 10.1039/b707495f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The quest for athletic excellence holds no limit for some athletes, and the advances in recombinant DNA technology have handed these athletes the ultimate doping weapons: recombinant proteins and gene doping. Some detection methods are now available for several recombinant proteins that are commercially available as pharmaceuticals and being abused by dopers. However, researchers are struggling to come up with efficient detection methods in preparation for the imminent threat of gene doping, expected in the 2008 Olympics. This Forum article presents the main detection strategies for recombinant proteins and the forthcoming detection strategies for gene doping as well as the prime analytical challenges facing them.
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Affiliation(s)
- Hassan M E Azzazy
- Department of Chemistry and Yousef Jameel Science & Technology Research Center, Sci Bldg # 310, The American University in Cairo, 113 Kasr El-Aini Street, Cairo 11511, Egypt.
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17
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Yu B, Cong H, Liu H, Li Y, Liu F. Ionene-dynamically coated capillary for analysis of urinary and recombinant human erythropoietin by capillary electrophoresis and online electrospray ionization mass spectrometry. J Sep Sci 2006; 28:2390-400. [PMID: 16342807 DOI: 10.1002/jssc.200500156] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this article, a series of ionene polymers were synthesized and used to coat fused-silica capillaries for the separation of recombinant and urinary human erythropoietin (rhEPO and uEPO) standards by CE. The influence of the charge density of coatings on the separation of rhEPO and uEPO glycoforms was investigated. Then, we further studied the method for fast separation and detection of rhEPO and uEPO standards by CE-ESI-MS. The influence of several CE and MS operating parameters, such as the concentration of CE running buffer, applied external pressure, and the composition and flow rate of sheath liquid on CE-ESI-MS was studied. The results demonstrated that when the capillary was permanently coated with 6,6-ionene and the pH value of acetic acid-ammonium acetate running buffer was 4.80 and 5.50, respectively, a significantly reproducible separation was achieved for rhEPO and uEPO glycoforms. In the online CE-ESI-MS experiments, we not only achieved the online MS signal of uEPO, but also obtained baseline separation of three major rhEPO glycoforms successfully and reproducibly on the 6,6-ionene-coated capillaries. Furthermore, the standard mixture of rhEPO and uEPO was separated, and two incompletely resolved peaks that were identified to be rhEPO and uEPO by the unique MS "fingerprint" were obtained. Additionally, the molecular weight of rhEPO and uEPO were verified and compared to the results by MALDI-TOF-MS. It can be concluded that, in contrast to other indirect methods, the online CE-ESI-MS technique with the combination of the advantages of both CE and MS shows great potential for the separation and detection of rhEPO doping directly in competitive sports.
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Affiliation(s)
- Bing Yu
- The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
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18
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Azzazy HME, Mansour MMH, Christenson RH. Doping in the recombinant era: strategies and counterstrategies. Clin Biochem 2006; 38:959-65. [PMID: 16286094 DOI: 10.1016/j.clinbiochem.2005.09.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Revised: 08/30/2005] [Accepted: 09/02/2005] [Indexed: 12/01/2022]
Abstract
Advances in recombinant DNA technology have created one of the most powerful weapons in the current doping arsenal: recombinant proteins [Sweeney HL. Gene doping. Sci Am 2004;291:62-9; Unal M, Ozer Unal D. Gene doping in sports. Sports Med 2004;34:357-62]. Recombinant erythropoietin (EPO) and human growth hormone (hGH) are currently being abused but are fortunately detectable either directly by employing isoelectric focusing and immunoassays or indirectly by assessing changes in selected hematopoietic parameters. The detection is technically demanding due to the extent of similarity between the recombinant proteins and their endogenous counterparts. Another issue facing detection efforts is the speed and conditions at which blood samples are collected and analyzed in a sports setting. Recently, gene doping, which stemmed out of legitimate gene therapy trials, has emerged as the next level of doping. Erythropoietin (EPO), human growth hormone (hGH), insulin-like growth factor-1 (IGF-1), peroxisome proliferator-activated receptor-delta (PPAR delta), and myostatin inhibitor genes have been identified as primary targets for doping. Sports clinical scientists today are racing against the clock because assuring the continued integrity of sports competition depends on their ability to outpace the efforts of dopers by developing new detection strategies.
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Affiliation(s)
- Hassan M E Azzazy
- Department of Chemistry and Science & Technology Research Center, The American University in Cairo, Cairo, Egypt.
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Tagliaro F, Bortolotti F. Recent advances in the applications of CE to forensic sciences (2001–2004). Electrophoresis 2006; 27:231-43. [PMID: 16421953 DOI: 10.1002/elps.200500697] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The present article reviews the applications of CE in forensic science covering the period from 2001 until the first part of 2005. The overview includes the most relevant examples of analytical applications of capillary electrophoretic and electrokinetic techniques in the following fields: (i) Forensic drugs and poisons, (ii) explosive analysis and gunshot residues, (iii) small ions of forensic interest, (iv) forensic DNA and RNA analysis, (v) proteins of forensic interest, and (vi) ink analysis.
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Affiliation(s)
- Franco Tagliaro
- Department of Public Medicine and Health, Section of Forensic Medicine, University of Verona, Verona, Italy.
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Madajová V, Simunicová E, Kaniansky D, Marák J, Zelenská V. Fractionation of glycoforms of recombinant human erythropoietin by preparative capillary isotachophoresis. Electrophoresis 2005; 26:2664-73. [PMID: 15929059 DOI: 10.1002/elps.200500044] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This feasibility study deals with the use of preparative capillary isotachophoresis (CITP), operating in a discontinuous fractionation mode, to the separations and isolations of glycoforms of recombinant human erythropoietin (rhEPO). The preparative CITP separations were monitored by capillary zone electrophoresis (CZE) with a hydrodynamically closed separation unit. Such a CZE system, suppressing fluctuations of the migration data linked with fluctuations of EOF and hydrodynamic flow, made possible to evaluate and compare the preparative CITP separations performed within a longer time frame. Preparative CITP, carried out in the separation unit with coupled columns of enhanced sample loadability, separating 100 microg of rhEPO in a run lasting ca. 30 min, gave the production rate higher than 55 ng/s for the rhEPO glycoforms. The preparative separations included valve isolations of the glycoforms from the ITP stack into four or six fractions. Such numbers of the fractions corresponded to typical numbers of the major glycoform peaks as resolved in CZE of rhEPO. With respect to close effective mobilities of the glycoforms and a multicomponent nature of rhEPO, the fractions contained mixtures of glycoforms with the dominant glycoforms enriched 10-100-fold, relative to the original rhEPO sample.
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Affiliation(s)
- Vlasta Madajová
- Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
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21
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Stübiger G, Marchetti M, Nagano M, Reichel C, Gmeiner G, Allmaier G. Characterisation of intact recombinant human erythropoietins applied in doping by means of planar gel electrophoretic techniques and matrix-assisted laser desorption/ionisation linear time-of-flight mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:728-742. [PMID: 15700237 DOI: 10.1002/rcm.1830] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Our experiments show that it is possible to detect different types of recombinant human erythropoietins (rhEPOs), EPO-alpha, EPO-beta and novel erythropoesis stimulating protein (NESP), based on exact molecular weight (MW) determination by matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) applying a high-resolution time-of-flight (TOF) mass analyser in the linear mode. Detection limits for the highly purified, intact glycoproteins were achievable in the low fmol range (25-50 fmol) using a sample preparation method applying a hydrophobic sample support (DropStop) as MALDI target surface. These results are very promising for the development of highly sensitive detection methods for a direct identification of rhEPO after enrichment from human body fluids. During our investigation we were able to differentiate EPO-alpha, EPO-beta and NESP based on distinct molecular substructures at the protein level by specific enzymatic reactions. MW determination of the intact molecules by high resolving one-dimensional sodium dodecyl sulfate /polyacrylamide gel electrophoresis (1D SDS-PAGE) and isoform separation by planar isoelectric focusing (IEF) was compared with MALDI-MS data. Migration differences between the rhEPOs were observed from gel electrophoresis, whereby MWs of 38 kDa in the case of EPO-alpha/beta and 49 kDa for NESP could be estimated. In contrast, an exact MW determination by MALDI-MS based on internal calibration revealed average MWs of 29.8 +/- 0.3 kDa for EPO-alpha/beta and 36.8 +/- 0.4 kDa for NESP. IEF separation of the intact rhEPOs revealed the presence of four to eight distinct isoforms in EPO-alpha and EPO-beta, while four isoforms, which appeared in the more acidic area of the gels, were detected by immunostaining in NESP. A direct detection of the different N- or O-glycoform pattern from rhEPOs using MALDI-MS was possible by de-sialylation of the glycan structures and after de-N-glycosylation of the intact molecules. Thereby, the main glycoforms of EPO-alpha, EPO-beta and NESP could be characterised based on their N-glycan composition. A microheterogeneity of the molecules based on the degree of sialylation of the O-glycan was observable directly from the de-N-glycosylated protein.
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Affiliation(s)
- Gerald Stübiger
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, A-1060 Vienna, Austria
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