1
|
Sutton H, Hong F, Han X, Rauniyar N. Analysis of therapeutic monoclonal antibodies by imaged capillary isoelectric focusing (icIEF). ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:5450-5458. [PMID: 39042476 DOI: 10.1039/d4ay00836g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Imaged capillary isoelectric focusing (icIEF) is a preferred analytical method for determining isoelectric points (pIs) and charge heterogeneity profiles in biotherapeutic proteins. In this study, we optimized the icIEF method for an in-house IgG1κ monoclonal antibody (mAb-1) and assessed its reproducibility, robustness, and autosampler stability. The optimized method was used to evaluate batch-to-batch consistency in pIs for multiple lots of mAb-1 and determine the relative percentages of charge variants. We also tested the method's performance using multiple lots of another IgG1 mAb, commercially available as Herceptin (trastuzumab). Additionally, we designed and assessed native and denaturing platform icIEF methods for 11 other marketed mAbs, with pIs ranging from 6.0 (eculizumab) to 9.22 (tocilizumab).
Collapse
Affiliation(s)
- Haley Sutton
- Tanvex Biopharma USA, Inc., 10394 Pacific Center Ct, San Diego, CA 92121, USA.
| | - Feng Hong
- Tanvex Biopharma USA, Inc., 10394 Pacific Center Ct, San Diego, CA 92121, USA.
| | - Xuemei Han
- Tanvex Biopharma USA, Inc., 10394 Pacific Center Ct, San Diego, CA 92121, USA.
| | - Navin Rauniyar
- Tanvex Biopharma USA, Inc., 10394 Pacific Center Ct, San Diego, CA 92121, USA.
| |
Collapse
|
2
|
Yu Z, Cao Y, Tian Y, Ji W, Chen KE, Wang Z, Ren J, Xiao H, Zhang L, Liu W, Fan L, Zhang Q, Cao C. Real-time and quantitative protein detection via polyacrylamide gel electrophoresis and online intrinsic fluorescence imaging. Anal Chim Acta 2024; 1291:342219. [PMID: 38280790 DOI: 10.1016/j.aca.2024.342219] [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: 12/19/2023] [Accepted: 01/05/2024] [Indexed: 01/29/2024]
Abstract
The detection of intrinsic protein fluorescence is a powerful tool for studying proteins in their native state. Thanks to its label-free and stain-free feature, intrinsic fluorescence detection has been introduced to polyacrylamide gel electrophoresis (PAGE), a fundamental and ubiquitous protein analysis technique, to avoid the tedious detection process. However, the reported methods of intrinsic fluorescence detection were incompatible with online PAGE detection or standard slab gel. Here, we fulfilled online intrinsic fluorescence imaging (IFI) of the standard slab gel to develop a PAGE-IFI method for real-time and quantitative protein detection. To do so, we comprehensively investigated the arrangement of the deep-UV light source to obtain a large imaging area compatible with the standard slab gel, and then designed a semi-open gel electrophoresis apparatus (GEA) to scaffold the gel for the online UV irradiation and IFI with low background noise. Thus, we achieved real-time monitoring of the protein migration, which enabled us to determine the optimal endpoint of PAGE run to improve the sensitivity of IFI. Moreover, online IFI circumvented the broadening of protein bands to enhance the separation resolution. Because of the low background noise and the optimized endpoint, we showcased the quantitative detection of bovine serum albumin (BSA) with a limit of detection (LOD) of 20 ng. The standard slab gel provided a high sample loading volume that allowed us to attain a wide linear range of 0.03-10 μg. These results indicate that the PAGE-IFI method can be a promising alternative to conventional PAGE and can be widely used in molecular biology labs.
Collapse
Affiliation(s)
- Zixian Yu
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yiren Cao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Youli Tian
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Weicheng Ji
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ke-Er Chen
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, China
| | - Zihao Wang
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hua Xiao
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Lu Zhang
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Weiwen Liu
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Liuyin Fan
- Student Innovation Center, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Qiang Zhang
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Chengxi Cao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China.
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Hajba L, Jeong S, Chung DS, Guttman A. Capillary Gel Electrophoresis of Proteins: Historical overview and recent advances. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.117024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
|
5
|
Xu T, Han L, Sun L. Automated Capillary Isoelectric Focusing-Mass Spectrometry with Ultrahigh Resolution for Characterizing Microheterogeneity and Isoelectric Points of Intact Protein Complexes. Anal Chem 2022; 94:9674-9682. [PMID: 35766479 DOI: 10.1021/acs.analchem.2c00975] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein complexes are the functional machines in the cell and are heterogeneous due to protein sequence variations and post-translational modifications (PTMs). Here, we present an automated nondenaturing capillary isoelectric focusing-mass spectrometry (ncIEF-MS) methodology for uncovering the microheterogeneity of intact protein complexes. The method exhibited superior separation resolution for protein complexes than conventional native capillary zone electrophoresis (nCZE-MS). In our study, ncIEF-MS achieved liquid-phase separations and MS characterization of seven different forms of a streptavidin homotetramer with variations of N-terminal methionine removal, acetylation, and formylation and four forms of the carbonic anhydrase-zinc complex arising from variations of PTMs (succinimide, deamidation, etc.). In addition, ncIEF-MS resolved different states of an interchain cysteine-linked antibody-drug conjugate (ADC1) as a new class of anticancer therapeutic agents that bears a distribution of varied drug-to-antibody ratio (DAR) species. More importantly, ncIEF-MS enabled precise measurements of isoelectric points (pIs) of protein complexes, which reflect the surface electrostatic properties of protein complexes. We studied how protein sequence variations/PTMs modulate the pIs of protein complexes and how drug loading affects the pIs of antibodies. We discovered that keeping the N-terminal methionine residue of one subunit of the streptavidin homotetramer decreased its pI by 0.1, adding one acetyl group onto the streptavidin homotetramer reduced its pI by nearly 0.4, incorporating one formyl group onto the streptavidin homotetramer reduced its pI by around 0.3, and loading two more drug molecules on one ADC1 molecule increased its pI by 0.1. The data render the ncIEF-MS method a valuable tool for delineating protein complexes.
Collapse
Affiliation(s)
- Tian Xu
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, Unites States
| | - Linjie Han
- New Biological Entities (NBE), Analytical R&D, AbbVie Inc., 1 Waukegan Rd, North Chicago, Illinois 60064, United States
| | - Liangliang Sun
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, Unites States
| |
Collapse
|
6
|
Abstract
The rules of fair play in sport generally prohibit the use of performance-enhancing drugs (PEDs). The World Anti-Doping Agency (WADA) oversees global antidoping regulations and testing for elite athletes participating in Olympic sports. Efforts to enforce antidoping policies are complicated by the diverse and evolving compounds and strategies employed by athletes to gain a competitive edge. Now between the uniquely proximate 2021 Tokyo and 2022 Beijing Olympic Games, we discuss WADA's efforts to prevent PED use during the modern Olympic Games. Then, we review the major PED classes with a focus on pathophysiology, complexities of antidoping testing, and relevant toxicities. Providers from diverse practice environments are likely to care for patients using PEDs for a variety of reasons and levels of sport; these providers should be aware of common PED classes and their risks.
Collapse
Affiliation(s)
- C James Watson
- Harvard Medical Toxicology Program, Boston Children's Hospital, Boston, MA, USA.,Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Genevra L Stone
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Daniel L Overbeek
- Harvard Medical Toxicology Program, Boston Children's Hospital, Boston, MA, USA.,Department of Emergency Medicine, University of Rochester, Rochester, NY, USA
| | - Takuyo Chiba
- Department of Emergency Medicine, International University of Health and Welfare, Ōtawara, Japan
| | - Michele M Burns
- Harvard Medical Toxicology Program, Boston Children's Hospital, Boston, MA, USA.,Division of Emergency Medicine, Boston Children's Hospital, Boston, MA, USA
| |
Collapse
|
7
|
Gholami MD, Theiss F, Sonar P, Ayoko GA, Izake EL. Rapid and selective detection of recombinant human erythropoietin in human blood plasma by a sensitive optical sensor. Analyst 2021; 145:5508-5515. [PMID: 32598413 DOI: 10.1039/d0an00972e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recombinant human erythropoietin (rHuEPO) is an important hormone drug that is used to treat several medical conditions. It is also frequently abused by athletes as a performance enhancing agent at sporting events. The time window of the rHuEPO in blood is short. Therefore, the rapid detection of rHuEPO use/abuse at points of care and in sports requires a selective analytical method and a sensitive sensor. Herein, we present a highly selective method for the rapid detection of rHuEPO in human blood plasma by a sensitive optical sensor. rHuEPO is selectively extracted from human blood plasma by a target-specific extractor chip and converted into a biothiol by reducing its disulfide bond structure. The formed biothiol reacts with a water soluble (E)-1-((6-methoxybenzo[d]thiazole-2-yl)diazenyl)naphthalene-2,6-diolHg(ii) (BAN-Hg) optical sensor and causes its rapid decomposition. This leads to a rapid change in the sensor color from blue to pink that can be observed by the naked eye. The optical sensor was used to quantify rHuEPO in the concentration range 1 × 10-8 M to 1 × 10-12 M by UV-Vis spectroscopy. For the screening of blood plasma, an EPO-specific extractor chip was synthesized and used to selectively extract the protein from the biological matrix prior to its conversion into biothiol and quantification by the optical sensor. Since many proteins have a disulfide bond structure, the new method has strong potential for their rapid sensitive and selective detection by the BAN-Hg sensor and UV-Vis spectroscopy.
Collapse
Affiliation(s)
- Mahnaz D Gholami
- Queensland University of Technology (QUT), School of Chemistry and Physics, 2 George street QLD, 4000, Australia.
| | - Frederick Theiss
- Queensland University of Technology (QUT), School of Chemistry and Physics, 2 George street QLD, 4000, Australia.
| | - Prashant Sonar
- Queensland University of Technology (QUT), School of Chemistry and Physics, 2 George street QLD, 4000, Australia. and Centre for Material Science, Queensland University of Technology (QUT), 2 George street QLD, 4000, Australia
| | - Godwin A Ayoko
- Queensland University of Technology (QUT), School of Chemistry and Physics, 2 George street QLD, 4000, Australia. and Centre for Material Science, Queensland University of Technology (QUT), 2 George street QLD, 4000, Australia
| | - Emad L Izake
- Queensland University of Technology (QUT), School of Chemistry and Physics, 2 George street QLD, 4000, Australia. and Centre for Material Science, Queensland University of Technology (QUT), 2 George street QLD, 4000, Australia
| |
Collapse
|
8
|
Li X, Yu L, Shi X, Rao C, Zhou Y. Capillary isoelectric focusing with UV fluorescence imaging detection enables direct charge heterogeneity characterization of erythropoietin drug products. J Chromatogr A 2021; 1643:462043. [PMID: 33780879 DOI: 10.1016/j.chroma.2021.462043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/13/2021] [Accepted: 03/02/2021] [Indexed: 10/21/2022]
Abstract
An imaged capillary isoelectric focusing (icIEF) - UV fluorescence imaging detection method is described for the direct charge heterogeneity characterization of recombinant human erythropoietin (rhEPO) drug products (DPs). rhEPO is one of the most important protein therapeutics for biopharmaceutical industry worldwide. As a heavily glycosylated protein therapeutic, its charge heterogeneity must be carefully monitored in each step of manufacturing and storage. Current charge characterization methods suffer from challenges to characterize rhEPO DPs, due to low sensitivity of the method and potential for interference from the DP's formulation. The method described herein leverages the separation power of imaged cIEF separation combined with the increased sensitivity afforded by UV fluorescence imaging detection and requires no pre-treatment of the DP sample prior to analysis. The method was evaluated initially using a simulated DP, and subsequently a mini method validation was performed using a commercial rhEPO DP sample according to the guideline set by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). The limit of quantitation (LOQ) of the method is validated to be 20.3 IU/mL (or 0.10 µg/mL), which is approximately 100 times more sensitive than CZE - UV absorption detection method. To demonstrate the applicability of the method for use, 8 different commercial rhEPO DPs with concentrations ranging from 2000 IU/mL - 10,000 IU/mL were successfully evaluated. This method allows for sensitive, rapid analysis of low concentration rhEPO drug products without sample pre-treatment to provide critical charge heterogeneity information.
Collapse
Affiliation(s)
- Xiang Li
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing 100050, China
| | - Lei Yu
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing 100050, China
| | - Xinchang Shi
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing 100050, China
| | - Chunming Rao
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing 100050, China.
| | - Yong Zhou
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing 100050, China.
| |
Collapse
|
9
|
Ren TJ, Zhang XX, Li X, Chen HX. Isoforms analysis of recombinant human erythropoietin by polarity-reversed capillary isoelectric focusing. Electrophoresis 2020; 41:2055-2061. [PMID: 32841408 DOI: 10.1002/elps.202000165] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 12/28/2022]
Abstract
Recombinant human erythropoietin (rhuEPO) has been extensively used as a pharmaceutical product for treating anemia in the clinic. Glycosylation of rhuEPO was crucial for affecting biological activity, immunogenicity, and pharmacokinetics. Because of the heterogeneity of glycan, the structure of rhuEPO was complex with several isoforms. Characterization of isoforms was important for quality control of rhuEPO. Here, an improved cIEF method has been established and validated. A polarity-reversed focusing step was used by reversing both the polarity of the voltage and the catholyte and anolyte vials. A weak base (100 mM ammonium hydroxide solution) was used as a chemical mobilizer to make the acidic bands mobilize stably to the detection window. Compared with CZE method in European Pharmacopoeia, the numbers of isoforms and their peak area percentage were highly consistent. Better reproducibility and higher resolution have been obtained by the improved cIEF method. Moreover, in improved cIEF method, the isoelectric points (pI) of each isoform can be calculated and used for identification. It was also the first time that the cIEF method was fully validated for rhuEPO analysis according to the International Conference on Harmonization (ICH) guidelines.
Collapse
Affiliation(s)
| | | | - Xiang Li
- Division of Recombinant Biological Products, National Institute of Food and Drug Control (NIFDC), Beijing, P. R. China
| | | |
Collapse
|
10
|
Li X, Shi X, Qin X, Yu L, Zhou Y, Rao C. Interlaboratory method validation of imaged capillary isoelectric focusing methodology for analysis of recombinant human erythropoietin. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:3836-3843. [PMID: 32678383 DOI: 10.1039/d0ay00823k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Recombinant human erythropoietin (rhEPO) is one of the most important biopharmaceuticals worldwide, with global sales expected to reach US$11.9 billion in 2020. The charge heterogeneity of rhEPO must be monitored throughout the entire production process. Imaged capillary isoelectric focusing (icIEF) is a promising method for monitoring rhEPO charge heterogeneity, but it must be validated according to the ICH guideline (International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use). Here, a multi-laboratory joint method validation of the icIEF method for rhEPO analysis was performed according to the ICH Harmonized Tripartite Guideline on Analysis Procedure. This guideline includes specificity, precision, accuracy, linearity, range, LOQ and robustness, whereby precision is defined by the repeatability, intermediate precision and reproducibility.
Collapse
Affiliation(s)
- Xiang Li
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing, 100050, China.
| | | | | | | | | | | |
Collapse
|
11
|
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
| |
Collapse
|
12
|
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
| |
Collapse
|
13
|
Ju HX, Zhuang QK, Long YT. The Preface. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2016.11.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
14
|
Zhao YY, Wang N, Liu WH, Tao WJ, Liu LL, Shen ZD. Charge Variants of an Avastin Biosimilar Isolation, Characterization, In Vitro Properties and Pharmacokinetics in Rat. PLoS One 2016; 11:e0151874. [PMID: 26987122 PMCID: PMC4795741 DOI: 10.1371/journal.pone.0151874] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 03/04/2016] [Indexed: 12/22/2022] Open
Abstract
The similarity between a proposed biosimilar product and the reference product can be affected by many factors. This study is designed to examine whether any subtle difference in the distribution of the charge variants of an Avastin biosimilar can affect its in vitro potency and in vivo PK. Here, the acidic, basic and main peak fractions of a biosimilar product were isolated using high-performance cation-exchange chromatography and were subjected to various studies to compare their in vitro properties and in vivo PK profile. A serial of analytical methods, including size exclusion chromatography (SEC), imaged capillary isoelectric focusing (icIEF) capillary zone electrophoresis (CZE) and cation-exchange chromatography (CEX-HPLC) were also used to characterize the isolated charge variants. The kinetics constant was measured using a Biacore X100 system. The study indicates the biosimilar product has a high similarity with avastin in physicochemical properties. The potency in vitro and PK profile in rat of charge variants and biosimilar product are consistent with avastin.
Collapse
Affiliation(s)
- Yan-Yan Zhao
- School of Pharmacy, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Yantai University, Yantai, 264005, P.R. China
- State Key Laboratory of Long-acting and Targeting Drug Delivery System, Luye Pharma Group Ltd., Yantai, 264005, P.R. China
| | - Ning Wang
- School of Pharmacy, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Yantai University, Yantai, 264005, P.R. China
| | - Wan-Hui Liu
- School of Pharmacy, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Yantai University, Yantai, 264005, P.R. China
- State Key Laboratory of Long-acting and Targeting Drug Delivery System, Luye Pharma Group Ltd., Yantai, 264005, P.R. China
- * E-mail:
| | - Wen-Jie Tao
- State Key Laboratory of Long-acting and Targeting Drug Delivery System, Luye Pharma Group Ltd., Yantai, 264005, P.R. China
| | - Li-Li Liu
- State Key Laboratory of Long-acting and Targeting Drug Delivery System, Luye Pharma Group Ltd., Yantai, 264005, P.R. China
| | - Zhen-Duo Shen
- State Key Laboratory of Long-acting and Targeting Drug Delivery System, Luye Pharma Group Ltd., Yantai, 264005, P.R. China
| |
Collapse
|
15
|
Girard M, Kane A, Boucher S. Capillary Electrophoresis Method for the Assessment of Erythropoiesis-Stimulating Agents in Final Formulations. Methods Mol Biol 2016; 1466:165-177. [PMID: 27473489 DOI: 10.1007/978-1-4939-4014-1_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Capillary electrophoresis (CE) comprises several separation modes that can be used to characterize proteins in terms of physico-chemical properties such as isoelectric point or molecular weight, or in terms of purity/heterogeneity for the presence of charge or size variants. In glycoproteins the heterogeneity occurring as a consequence of variable amounts of terminal sialic acid residues on glycan moieties can be detected by CE. As such, a capillary zone electrophoresis (CZE) method was found suitable for the detection of isoforms of several erythropoiesis-stimulating agents (Bietlot and Girard, J Chromatogr A 759:177-184, 1997; Boucher et al., J Pharm Biomed Anal 71:207-213, 2012). In particular, the method can be used to analyze finished products containing erythropoietin-α, erythropoietin-β, or darbepoetin-α regardless of the formulation and without the need for sample pretreatment. The major excipients encountered in the various formulations included polysorbate 80, polysorbate 20, or human serum albumin. The ability of the method to resolve isoforms of the active ingredient in finished product enables the comparison of the isoform profile with that of the corresponding drug substance, allowing the assessment of the structural integrity and content of the active ingredients in finished products.
Collapse
Affiliation(s)
- Michel Girard
- Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, Canada, K1A 0K9.
| | - Anita Kane
- Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, Canada, K1A 0K9
| | - Sylvie Boucher
- Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, Canada, K1A 0K9
| |
Collapse
|
16
|
Ahmed HM, Ebeid WB. The use of laser-induced fluorescence or ultraviolet detectors for sensitive and selective analysis of tobramycin or erythropoietin in complex samples. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 143:12-19. [PMID: 25706680 DOI: 10.1016/j.saa.2015.02.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/29/2015] [Accepted: 02/04/2015] [Indexed: 06/04/2023]
Abstract
Complex samples analysis is a challenge in pharmaceutical and biopharmaceutical analysis. In this work, tobramycin (TOB) analysis in human urine samples and recombinant human erythropoietin (rhEPO) analysis in the presence of similar protein were selected as representative examples of such samples analysis. Assays of TOB in urine samples are difficult because of poor detectability. Therefore laser induced fluorescence detector (LIF) was combined with a separation technique, micellar electrokinetic chromatography (MEKC), to determine TOB through derivatization with fluorescein isothiocyanate (FITC). Borate was used as background electrolyte (BGE) with negative-charged mixed micelles as additive. The method was successively applied to urine samples. The LOD and LOQ for Tobramycin in urine were 90 and 200ng/ml respectively and recovery was >98% (n=5). All urine samples were analyzed by direct injection without sample pre-treatment. Another use of hyphenated analytical technique, capillary zone electrophoresis (CZE) connected to ultraviolet (UV) detector was also used for sensitive analysis of rhEPO at low levels (2000IU) in the presence of large amount of human serum albumin (HSA). Analysis of rhEPO was achieved by the use of the electrokinetic injection (EI) with discontinuous buffers. Phosphate buffer was used as BGE with metal ions as additive. The proposed method can be used for the estimation of large number of quality control rhEPO samples in a short period.
Collapse
Affiliation(s)
- Hytham M Ahmed
- Pharmaceutical Analysis Department, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt.
| | - Wael B Ebeid
- SEDICO Pharmaceuticals, Merck & Co External Partner, 6th of October City, Cairo, Egypt
| |
Collapse
|
17
|
Loughney JW, Rustandi RR, Wang D, Troutman MC, Dick LW, Li G, Liu Z, Li F, Freed DC, Price CE, Hoang VM, Culp TD, DePhillips PA, Fu TM, Ha S. Soluble Human Cytomegalovirus gH/gL/pUL128-131 Pentameric Complex, but Not gH/gL, Inhibits Viral Entry to Epithelial Cells and Presents Dominant Native Neutralizing Epitopes. J Biol Chem 2015; 290:15985-95. [PMID: 25947373 DOI: 10.1074/jbc.m115.652230] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Indexed: 11/06/2022] Open
Abstract
Congenital infection of human cytomegalovirus (HCMV) is one of the leading causes of nongenetic birth defects, and development of a prophylactic vaccine against HCMV is of high priority for public health. The gH/gL/pUL128-131 pentameric complex mediates HCMV entry into endothelial and epithelial cells, and it is a major target for neutralizing antibody responses. To better understand the mechanism by which antibodies interact with the epitopes of the gH/gL/pUL128-131 pentameric complex resulting in viral neutralization, we expressed and purified soluble gH/gL/pUL128-131 pentameric complex and gH/gL from Chinese hamster ovary cells to >95% purity. The soluble gH/gL, which exists predominantly as (gH/gL)2 homodimer with a molecular mass of 220 kDa in solution, has a stoichiometry of 1:1 and a pI of 6.0-6.5. The pentameric complex has a molecular mass of 160 kDa, a stoichiometry of 1:1:1:1:1, and a pI of 7.4-8.1. The soluble pentameric complex, but not gH/gL, adsorbs 76% of neutralizing activities in HCMV human hyperimmune globulin, consistent with earlier reports that the most potent neutralizing epitopes for blocking epithelial infection are unique to the pentameric complex. Functionally, the soluble pentameric complex, but not gH/gL, blocks viral entry to epithelial cells in culture. Our results highlight the importance of the gH/gL/pUL128-131 pentameric complex in HCMV vaccine design and emphasize the necessity to monitor the integrity of the pentameric complex during the vaccine manufacturing process.
Collapse
Affiliation(s)
| | | | | | | | | | - Guanghua Li
- Biologics Bioprocess Development, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - Zhong Liu
- Biologics Bioprocess Development, Merck Research Laboratories, West Point, Pennsylvania 19486
| | | | | | | | - Van M Hoang
- From the Vaccine Bioprocess Research & Development
| | | | | | | | - Sha Ha
- From the Vaccine Bioprocess Research & Development,
| |
Collapse
|
18
|
Tamizi E, Jouyban A. The potential of the capillary electrophoresis techniques for quality control of biopharmaceuticals-A review. Electrophoresis 2015; 36:831-58. [DOI: 10.1002/elps.201400343] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/27/2014] [Accepted: 11/27/2014] [Indexed: 12/24/2022]
Affiliation(s)
- Elnaz Tamizi
- Biotechnology Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Abolghasem Jouyban
- Pharmacy Faculty and Drug Applied Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| |
Collapse
|
19
|
|
20
|
Jiang J, Tian F, Cai Y, Qian X, Costello CE, Ying W. Site-specific qualitative and quantitative analysis of the N- and O-glycoforms in recombinant human erythropoietin. Anal Bioanal Chem 2014; 406:6265-74. [PMID: 25080026 DOI: 10.1007/s00216-014-8037-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 12/25/2022]
Abstract
Recombinant human erythropoietin (rhEPO) has been extensively used as a pharmaceutical product for treating anemia. Glycosylation of rhEPO affects the biological activity, immunogenicity, pharmacokinetics, and in-vivo clearance rate of rhEPO. Characterization of the glycosylation status of rhEPO is of great importance for quality control. In this study, we established a fast and comprehensive approach for reliable characterization and relative quantitation of rhEPO glycosylation, which combines multiple-enzyme digestion, hydrophilic-interaction chromatography (HILIC) enrichment of glycopeptides, and tandem mass spectrometry (MS) analysis. The N-linked and O-linked intact glycopeptides were analyzed with high-resolution and high-accuracy (HR-AM) mass spectrometry using an Orbitrap. In total, 74 intact glycopeptides from four glycosylation sites at N24, N38, N83, and O126 were identified, with the simultaneous determination of peptide sequences and glycoform compositions. The extracted ion chromatograms based on the HR-AM data enabled relative quantification of glycoforms. Our results could be extended to quality control of rhEPO or could help establish detection approaches for glycosylation of other proteins.
Collapse
Affiliation(s)
- Jing Jiang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China
| | | | | | | | | | | |
Collapse
|
21
|
Zhao SS, Chen DDY. Applications of capillary electrophoresis in characterizing recombinant protein therapeutics. Electrophoresis 2013; 35:96-108. [PMID: 24123141 DOI: 10.1002/elps.201300372] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 12/15/2022]
Abstract
The use of recombinant protein for therapeutic applications has increased significantly in the last three decades. The heterogeneity of these proteins, often caused by the complex biosynthesis pathways and the subsequent PTMs, poses a challenge for drug characterization to ensure its safety, quality, integrity, and efficacy. CE, with its simple instrumentation, superior separation efficiency, small sample consumption, and short analysis time, is a well-suited analytical tool for therapeutic protein characterization. Different separation modes, including CIEF, SDS-CGE, CZE, and CE-MS, provide complementary information of the proteins. The CE applications for recombinant therapeutic proteins from the year 2000 to June 2013 are reviewed and technical concerns are discussed in this article.
Collapse
Affiliation(s)
- Shuai Sherry Zhao
- Department of Chemistry, University of British Columbia, Vancouver, Canada
| | | |
Collapse
|
22
|
Roseman DS, Weinberger R. Quantitative capillary zone electrophoresis method for the precise determination of charge differences arising from the manufacture of heparan-N-sulfatase. J Pharm Biomed Anal 2013; 85:67-73. [DOI: 10.1016/j.jpba.2013.05.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 05/01/2013] [Indexed: 11/26/2022]
|
23
|
Kinoshita M, Nakatsuji Y, Suzuki S, Hayakawa T, Kakehi K. Quality assurance of monoclonal antibody pharmaceuticals based on their charge variants using microchip isoelectric focusing method. J Chromatogr A 2013; 1309:76-83. [DOI: 10.1016/j.chroma.2013.08.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/25/2013] [Accepted: 08/06/2013] [Indexed: 12/18/2022]
|
24
|
Zhou CM. Characterization of human papillomavirus by capillary isoelectric focusing with whole-column imaging detection. Electrophoresis 2013; 34:3046-53. [DOI: 10.1002/elps.201300161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 07/17/2013] [Accepted: 07/17/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Chao-Ming Zhou
- Department of Quality Research; Shanghai Zerun Biotechnology Co., Ltd; Shanghai; China
| |
Collapse
|
25
|
Harrison CR. Role of Capillary Electrophoresis in the Fight Against Doping in Sports. Anal Chem 2013; 85:6982-7. [DOI: 10.1021/ac302821x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Christopher R. Harrison
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, California
92182, United States
| |
Collapse
|
26
|
Detection of EPO injections using a rapid lateral flow isoform test. Anal Bioanal Chem 2013; 405:9685-91. [DOI: 10.1007/s00216-013-6997-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 04/08/2013] [Accepted: 04/17/2013] [Indexed: 10/26/2022]
|
27
|
SUZUKI S. Recent Developments in Liquid Chromatography and Capillary Electrophoresis for the Analysis of Glycoprotein Glycans. ANAL SCI 2013; 29:1117-28. [DOI: 10.2116/analsci.29.1117] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
28
|
Markuszewski MJ, Bujak R, Daghir E. Capillary Isoelectric Focusing. SPRINGER SERIES IN CHEMICAL PHYSICS 2013. [DOI: 10.1007/978-3-642-35043-6_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
29
|
de Kort BJ, de Jong GJ, Somsen GW. Profiling of erythropoietin products by capillary electrophoresis with native fluorescence detection. Electrophoresis 2012; 33:2996-3001. [DOI: 10.1002/elps.201200303] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/05/2012] [Accepted: 08/02/2012] [Indexed: 12/22/2022]
|
30
|
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]
|
31
|
Anderson CL, Wang Y, Rustandi RR. Applications of imaged capillary isoelectric focussing technique in development of biopharmaceutical glycoprotein-based products. Electrophoresis 2012; 33:1538-44. [DOI: 10.1002/elps.201100611] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
32
|
Liu J, Ren L, Liu Y, Li H, Liu Z. Weak anion exchange chromatographic profiling of glycoprotein isoforms on a polymer monolithic capillary. J Chromatogr A 2012; 1228:276-82. [DOI: 10.1016/j.chroma.2011.08.079] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 08/13/2011] [Accepted: 08/21/2011] [Indexed: 10/17/2022]
|
33
|
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]
|
34
|
Ramsay LM, Cermak N, Dada OO, Dovichi NJ. Capillary isoelectric focusing with pH 9.7 cathode for the analysis of gastric biopsies. Anal Bioanal Chem 2011; 400:2025-30. [PMID: 21461616 PMCID: PMC4429874 DOI: 10.1007/s00216-011-4926-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 03/11/2011] [Accepted: 03/16/2011] [Indexed: 10/18/2022]
Abstract
Capillary isoelectric focusing tends to suffer from poor reproducibility, particularly for the analysis of complex protein samples from cellular or tissue homogenates. This poor reproducibility appears to be associated with erratic variations in electroosmotic flow. One cause of electroosmotic flow variation is degradation of the capillary coating caused by the extremely basic solution commonly used during mobilization and focusing; this degradation of the capillary coating can be reduced by employing a CAPS mobilization buffer at pH 9. Another cause of variation is protein adsorption to the capillary wall, which causes an increase in electroosmotic flow. The effects of protein adsorption can be reduced by use of surfactants in the buffer and by employing an extremely low sample loading. We report the use of CAPS mobilization buffer in combination with an ultrasensitive laser-induced fluorescence detector for the reproducible analysis of ∼2 ng of protein from a Barrett's esophagus biopsy.
Collapse
Affiliation(s)
- Lauren M. Ramsay
- Department of Chemistry, University of Washington, Seattle WA 98195 USA
| | - Nathan Cermak
- Program in Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge MA 02139 USA
| | - Oluwatosin O. Dada
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN 46617, USA
| | - Norman J. Dovichi
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN 46617, USA
| |
Collapse
|
35
|
Hua Y, Koshel BM, Wirth MJ. Field-free remobilization of proteins after isoelectric focusing in packed capillaries. Anal Chem 2010; 82:8910-5. [PMID: 20931968 DOI: 10.1021/ac101680z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pressure-driven remobilization without an applied electric field is shown to be possible with capillary isoelectric focusing using packed capillaries. The capillary dimensions are 100 μm i.d. and 2 cm in length, and the packing is made of 0.9 μm nonporous silica particles that are chemically modified with a brush layer of polyacrylamide. Both reversible and irreversible adsorption are shown to be negligible. The packed capillaries eliminate the problem of unwanted hydrodynamic flow between reservoirs. Three proteins are focused: trypsin inhibitor, carbonic anhydrase II, and myoglobin. The time required for focusing in the packed capillaries is increased by only a factor of 2 compared to the open capillary, giving complete focusing in less than 15 min at 200 V/cm. The packed capillaries allow the use of higher electric fields, with resolution continually increasing up to at least 1500 V/cm. The packing obstructs diffusional broadening after the field is turned off: for trypsin inhibitor, D = 6.1(±0.3) × 10(-8) cm(2)/s for the packed capillary vs D = 28.8(±0.3) × 10(-8) cm(2)/s for the open capillary. The broadening contributed by the packing during remobilization is from eddy diffusion, and it is described by its plate height, H, which is the variance per unit length: H = σ(2)/L = 0.64 μm. This limits the resolution to 0.1 pH units for the 2 cm capillary having a pH range of 3-10, giving a theoretical peak capacity of 47.
Collapse
Affiliation(s)
- Yimin Hua
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, United States, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | | | | |
Collapse
|
36
|
Capillary array isoelectric focusing with laser-induced fluorescence detection: milli-pH unit resolution and yoctomole mass detection limits in a 32-channel system. Anal Bioanal Chem 2010; 397:3305-10. [PMID: 20336452 DOI: 10.1007/s00216-010-3595-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 02/16/2010] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
Abstract
We report a multiplexed capillary electrophoresis system employing an array of 32 capillaries with a micromachined sheath-flow cuvette as the detection chamber. The sample streams were simultaneously excited with a 473-nm laser beam, and the fluorescence emission was imaged on a CCD camera with a pair of doublet achromat lens. The instrument produced mass detection limits of 380 +/- 120 yoctomoles for fluorescein in zone electrophoresis. Capillary isoelectric focusing of fluorescent standards produced peaks with an average width of 0.0029 +/- 0.0008 pH. Capillary coating stability limits the reproducibility of the analysis.
Collapse
|
37
|
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.
Collapse
Affiliation(s)
- Christian Reichel
- Austrian Research Centers GmbH - ARC, Doping Control Laboratory, A-2444, Seibersdorf, Austria.
| | | |
Collapse
|
38
|
|
39
|
|
40
|
Liu J, Liu Z, Kang M, Liu S, Chen HY. Combination of large volume sample stacking and reversed pH junction in capillary electrophoresis for online preconcentration of glycoforms of recombinant human erythropoietin. J Sep Sci 2009; 32:422-9. [DOI: 10.1002/jssc.200800387] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
41
|
Kamoda S, Kakehi K. Evaluation of glycosylation for quality assurance of antibody pharmaceuticals by capillary electrophoresis. Electrophoresis 2008; 29:3595-604. [DOI: 10.1002/elps.200700940] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|