1
|
Tsonev LI, Hirsh AG. Multiple, simultaneous, independent gradients for a versatile multidimensional liquid chromatography. Part II: Application 3 - Scouting optimization strategies for separation of monoclonal antibodies by dual simultaneous independent gradients of pH & salt on a weak cation exchange stationary phase. J Chromatogr A 2024; 1730:465065. [PMID: 38879974 DOI: 10.1016/j.chroma.2024.465065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/30/2024] [Accepted: 06/08/2024] [Indexed: 06/18/2024]
Abstract
In previous publications we have described the pISep dual simultaneous, independent gradients (DSIGs) liquid chromatography (LC) for uncoupling gradients of non-buffering solute (NaCl, urea or acetonitrile) from externally generated pH gradients. In DSIGs the shape and slope of the [salute] gradient does not depend on the shape and slope of the pH gradient. The technique allows in a single run true simultaneous two dimensional LC separation of complex protein mixtures on various stationary phases including anion, cation exchangers (AEX, CEX), reversed phase (RP), mixed mode and mixed bed. Using a humanized IgG1 (HIgG1) monoclonal antibody (MAb) and a variety of pH & [NaCl] DSIGs, we show that most of MAb isoforms can be successfully separated from each other. These experimental observations are supported by an initial theoretical argument presented here predicting an overall improvement of all MAb isoforms separation by DSIGs of pH & [NaCl]. Theoretical calculations predict that, in general, there exists an optimal non-zero isocratic salt concentration in a pH gradient separation that will resolve isoforms close in binding energy, but a wide range of salt concentrations will be required for acceptable resolution of all isoforms. Theory also predicts better separation of weaker rather than stronger binding isoforms. Experimentally, we have found that no one set of DSIGs LC conditions could optimally baseline resolve all identifiable MAb isoforms in a single run of reasonable duration. The versatility and simplicity of the pH & [NaCl] pISep DSIGs LC allows fast, automated scouting of protein separations over any range of pH from 2.4 to 10.8 and [NaCl] from 0 to 1 M without changing the chemistry of the buffering system. Due to the universal applicability of the pISep buffering system in IEX LC, the researcher is given a powerful tool to easily develop pH & [NaCl] DSIGs protocols that vary mobile phase compositions to achieve high resolution separations of targeted proteins.
Collapse
Affiliation(s)
- Latchezar I Tsonev
- CryoBioPhysica, Inc., 4620 N. Park Ave., #1502 w Chevy Chase, MD 20815, USA
| | - Allen G Hirsh
- CryoBioPhysica, Inc., 4620 N. Park Ave., #1502 w Chevy Chase, MD 20815, USA.
| |
Collapse
|
2
|
Farsang E, Horváth K, Beck A, Wang Q, Lauber M, Guillarme D, Fekete S. Impact of the column on effluent pH in cation exchange pH gradient chromatography, a practical study. J Chromatogr A 2020; 1626:461350. [PMID: 32797830 DOI: 10.1016/j.chroma.2020.461350] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/09/2020] [Accepted: 06/15/2020] [Indexed: 01/16/2023]
Abstract
In ionexchange chromatography, the pH gradient mode becomes more and more popular today for the analysis of therapeutic proteins as this mode can provide higher or alternative selectivity to the commonly used salt gradient mode. Ideally, a linear pH response is expected when performing linear gradients. However up to now, only a very few buffer systems have been developed and are commercially available which can perform nearly linear pH responses when flowing through a given column. It is also known that a selected buffer system (mobile phase) can work well on one column but can fail on other column. The goal of this study was to practically evaluate the effects that ionexchange columns (weak and strong exchangers) might have on effluent pH, when performing linear pH gradient separations of therapeutic monoclonal antibodies. To attain this objective, the pH was monitored on-line at the column outlet using a specific setup. To make comprehensive observations of the phenomenon, four different mobile phase conditions and five cation exchange columns (weak and strong exchangers) were employed. The obtained pH responses were systematically compared to responses measured in the absence of the columns. From this work, it has become clear that both the column and mobile phase can have significant effects on pH gradient chromatography and that their combination must be considered when developing a new method. Phase systems (column + mobile phase) providing linear pH responses are indeed the most suitable for separating mAbs with different isoelectric points and, with them, it is possible to elute mAbs across wide retention time ranges and with high selectivity.
Collapse
Affiliation(s)
- Evelin Farsang
- Department of Analytical Chemistry, University of Pannonia, Egyetem u. 10., H-8200 Veszprém, Hungary
| | - Krisztián Horváth
- Department of Analytical Chemistry, University of Pannonia, Egyetem u. 10., H-8200 Veszprém, Hungary
| | - Alain Beck
- Center of Immunology Pierre Fabre, 5 Avenue Napoléon III, BP 60497, 74160 Saint-Julien-en-Genevois, France
| | - Qi Wang
- Waters Corporation, 34 Maple Street, Milford, MA 01757-3696, United States; Current Address: Bristol Myers Squibb, 38 Jackson Rd, Devens, MA 01434, United States
| | - Matthew Lauber
- Waters Corporation, 34 Maple Street, Milford, MA 01757-3696, United States
| | - Davy Guillarme
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Szabolcs Fekete
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland.
| |
Collapse
|
3
|
Vetter TA, Ferreira G, Robbins D, Carta G. Resolution of Protein Charge Variants in Mixed-Bed Chromatography Columns with Step-Induced pH Gradients at High Protein Loadings. SEP SCI TECHNOL 2015. [DOI: 10.1080/01496395.2015.1040125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
4
|
Ohta Y, Iwamoto S, Kawabata SI, Tanimura R, Tanaka K. Salt Tolerance Enhancement of Liquid Chromatography-Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Using Matrix Additive Methylenediphosphonic Acid. Mass Spectrom (Tokyo) 2014; 3:A0031. [PMID: 26819873 DOI: 10.5702/massspectrometry.a0031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/26/2014] [Indexed: 11/23/2022] Open
Abstract
Mass spectrometry (MS) is a highly sensitive analytical technique that is often coupled with liquid chromatography (LC). However, some buffering salts used in LC (e.g., phosphate and tris(hydroxymethyl)aminomethane (Tris)) are incompatible with MS since they cause ion-source contamination and signal suppression. In this study, we examined salt tolerance of MALDI and applied a matrix additive methylenediphosphonic acid (MDPNA) to reduce salt-induced signal suppression. MDPNA significantly improved the salt tolerance of MALDI-MS. Using ammonium formate buffer at pH 5.0, the effective range of buffering salt concentration in MALDI-MS using MDPNA was estimated up to 250 mM. MDPNA reduced signal suppression caused by buffering salts at pH 4.0 to 8.0. We observed that MDPNA effectively worked over a wide range of buffer conditions. MDPNA was further applied to hydrophilic interaction chromatography (HILIC) and chromatofocusing-MALDI-MS. As a result, the analytes in the eluent containing high-concentration salts were detected with high sensitivity. Thus, our study provides simple and fast LC-MALDI-MS analysis technique not having strict limitation of buffering condition in LC by using matrix additive MDPNA.
Collapse
Affiliation(s)
- Yuki Ohta
- Koichi Tanaka Laboratory of Advanced Science and Technology, Shimadzu Corporation
| | - Shinichi Iwamoto
- Koichi Tanaka Laboratory of Advanced Science and Technology, Shimadzu Corporation
| | | | - Ritsuko Tanimura
- Koichi Tanaka Laboratory of Advanced Science and Technology, Shimadzu Corporation
| | - Koichi Tanaka
- Koichi Tanaka Laboratory of Advanced Science and Technology, Shimadzu Corporation
| |
Collapse
|
5
|
Ivanov AV. Using amino acids for the chromatofocusing of metal ions on silica with bonded tetraethylenepentamine groups. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2014. [DOI: 10.1134/s0036024414090179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
6
|
Vetter TA, Ferreira G, Robbins D, Carta G. Predicting Retention and Resolution of Protein Charge Variants in Mixed-Beds of Strong and Weak Anion Exchange Resins with Step-Induced pH Gradients. SEP SCI TECHNOL 2014. [DOI: 10.1080/01496395.2014.907810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
7
|
Vetter TA, Ferreira G, Robbins D, Carta G. Mixed-Beds of Strong and Weak Anion Exchange Resins for Protein Separations with Step-Induced pH Gradients. SEP SCI TECHNOL 2014. [DOI: 10.1080/01496395.2013.860169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
8
|
Choy DY, Creagh AL, von Lieres E, Haynes C. A new mixed-mode model for interpreting and predicting protein elution during isoelectric chromatofocusing. Biotechnol Bioeng 2014; 111:925-36. [DOI: 10.1002/bit.25166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 11/19/2013] [Accepted: 11/25/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Derek Y.C. Choy
- Michael Smith Laboratories; and the Department of Chemical and Biological Engineering; University of British Columbia; 231 Michael Smith Building Vancouver BC Canada V6T 1Z4
| | - A. Louise Creagh
- Michael Smith Laboratories; and the Department of Chemical and Biological Engineering; University of British Columbia; 231 Michael Smith Building Vancouver BC Canada V6T 1Z4
| | - Eric von Lieres
- Michael Smith Laboratories; and the Department of Chemical and Biological Engineering; University of British Columbia; 231 Michael Smith Building Vancouver BC Canada V6T 1Z4
- Institute of Bio- and Geosciences IBG-1: Biotechnology; Jülich GmbH; Jülich Germany
| | - Charles Haynes
- Michael Smith Laboratories; and the Department of Chemical and Biological Engineering; University of British Columbia; 231 Michael Smith Building Vancouver BC Canada V6T 1Z4
| |
Collapse
|
9
|
Guo H, Li X, Frey DD. Development of chromatofocusing techniques employing mixed-mode column packings for protein separations. J Chromatogr A 2014; 1323:57-65. [DOI: 10.1016/j.chroma.2013.10.090] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 10/14/2013] [Accepted: 10/30/2013] [Indexed: 10/26/2022]
|
10
|
Choy DY, Creagh AL, Haynes C. Improved isoelectric focusing chromatography on strong anion exchange media via a new model that custom designs mobile phases using simple buffers. Biotechnol Bioeng 2013; 111:552-64. [DOI: 10.1002/bit.25122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/10/2013] [Accepted: 09/16/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Derek Y.C. Choy
- Department of Chemical and Biological Engineering, Michael Smith Laboratories; University of British Columbia; Vancouver BC, Canada V6T 1Z4
| | - A. Louise Creagh
- Department of Chemical and Biological Engineering, Michael Smith Laboratories; University of British Columbia; Vancouver BC, Canada V6T 1Z4
| | - Charles Haynes
- Department of Chemical and Biological Engineering, Michael Smith Laboratories; University of British Columbia; Vancouver BC, Canada V6T 1Z4
| |
Collapse
|
11
|
Kang X, Kutzko JP, Hayes ML, Frey DD. Monoclonal antibody heterogeneity analysis and deamidation monitoring with high-performance cation-exchange chromatofocusing using simple, two component buffer systems. J Chromatogr A 2013; 1283:89-97. [DOI: 10.1016/j.chroma.2013.01.101] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 11/15/2022]
|
12
|
Hahn R. Methods for characterization of biochromatography media. J Sep Sci 2012; 35:3001-32. [DOI: 10.1002/jssc.201200770] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 08/22/2012] [Accepted: 08/23/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Rainer Hahn
- Department of Biotechnology; University of Natural Resources and Life Sciences; Vienna Austria
- Austrian Centre of Industrial Biotechnology; Vienna Austria
| |
Collapse
|
13
|
Hirsh AG, Tsonev LI. Multiple, simultaneous, independent gradients for versatile multidimensional liquid chromatography. Part I: Theory. J Chromatogr A 2012; 1236:51-62. [DOI: 10.1016/j.chroma.2012.02.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 02/21/2012] [Accepted: 02/26/2012] [Indexed: 10/28/2022]
|
14
|
Ng PK, Snyder MA. pH-based cation exchange chromatography in the capture and elution of monoclonal antibodies. J Sep Sci 2011; 35:29-35. [DOI: 10.1002/jssc.201100720] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 09/29/2011] [Accepted: 09/30/2011] [Indexed: 11/10/2022]
|
15
|
Farnan D, Moreno GT. Multiproduct High-Resolution Monoclonal Antibody Charge Variant Separations by pH Gradient Ion-Exchange Chromatography. Anal Chem 2009; 81:8846-57. [DOI: 10.1021/ac901408j] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dell Farnan
- Protein Analytical Chemistry, Genentech, 1 DNA Way, South San Francisco, California 94080
| | - G. Tony Moreno
- Protein Analytical Chemistry, Genentech, 1 DNA Way, South San Francisco, California 94080
| |
Collapse
|
16
|
Rozhkova A. Quantitative analysis of monoclonal antibodies by cation-exchange chromatofocusing. J Chromatogr A 2009; 1216:5989-94. [DOI: 10.1016/j.chroma.2009.06.045] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 05/10/2009] [Accepted: 06/12/2009] [Indexed: 11/30/2022]
|
17
|
Ng PK, He J, Snyder MA. Separation of protein mixtures using pH-gradient cation-exchange chromatography. J Chromatogr A 2009; 1216:1372-6. [DOI: 10.1016/j.chroma.2008.12.100] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 12/16/2008] [Accepted: 12/22/2008] [Indexed: 11/26/2022]
|
18
|
Pabst TM, Carta G, Ramasubramanyan N, Hunter AK, Mensah P, Gustafson ME. Separation of protein charge variants with induced pH gradients using anion exchange chromatographic columns. Biotechnol Prog 2008; 24:1096-106. [DOI: 10.1002/btpr.53] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
19
|
Tsonev LI, Hirsh AG. Theory and applications of a novel ion exchange chromatographic technology using controlled pH gradients for separating proteins on anionic and cationic stationary phases. J Chromatogr A 2008; 1200:166-82. [DOI: 10.1016/j.chroma.2008.05.076] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 05/14/2008] [Accepted: 05/22/2008] [Indexed: 11/25/2022]
|
20
|
Kim H, Lubman DM. Micro-proteome analysis using micro-chromatofocusing in intact protein separations. J Chromatogr A 2008; 1194:3-10. [PMID: 18407281 PMCID: PMC2479787 DOI: 10.1016/j.chroma.2008.03.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 03/14/2008] [Accepted: 03/18/2008] [Indexed: 01/23/2023]
Abstract
Multi-dimensional liquid-based separation is required for fractionation and mapping of complex protein mixtures from cells. A method that has been used as the first dimension in such separations is chromatofocusing (CF), which is based on generating a pH gradient on an anion exchange column. The use of pH in the first dimension is essential where pH is a fundamental property of proteins and can provide information on post-translationally modified forms of a protein. In this work, a micro-chromatofocusing technique is introduced which can separate microgram levels of proteins from cell lysates for further analysis by LC-MS/MS. It is shown that this method can analyze 10 microg of sample and detect nearly 700-800 proteins from ovarian cancer cell line lysates.
Collapse
Affiliation(s)
- Hyeyeung Kim
- Department of Chemistry, University of Michigan, 48109, Ann Arbor, MI, U.S.A
| | - David M. Lubman
- Department of Chemistry, University of Michigan, 48109, Ann Arbor, MI, U.S.A
- Department of Pathology, University of Michigan Medical Center, 48109, Ann Arbor, MI, U.S.A
- Department of Surgery, University of Michigan Medical Center, 48109, Ann Arbor, MI, U.S.A
- Comprehensive Cancer Center, University of Michigan, 48109, Ann Arbor, MI, U.S.A
| |
Collapse
|
21
|
Shen H, Li X, Bieberich CJ, Frey DD. Reducing sample complexity in proteomics by chromatofocusing with simple buffer mixtures. Methods Mol Biol 2008; 424:187-203. [PMID: 18369863 DOI: 10.1007/978-1-60327-064-9_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chromatofocusing has many potential applications in the field of proteomics, such as for the isolation and removal of major sample components to facilitate the analysis of low-abundance components, and for sample prefractionation prior to a subsequent separation using SDS-PAGE, narrow-pI-range 2D-PAGE, or additional chromatography steps. However, the chromatofocusing techniques that are most commonly used employ propriety polyampholyte elution buffers and highly specialized column packings, both of which limit the use of chromatofocusing in practice. To expand the range of application for this technique, this chapter considers chromatofocusing methods which employ common ion-exchange column packings and elution buffers which are simple mixtures of readily available buffering species. Of particular interest is the use of chromatofocusing with a multistep pH gradient for the fractionation of protein mixtures into narrow-pI-range fractions. The cross-contamination characteristics of these fractions using SDS-PAGE are also assessed.
Collapse
Affiliation(s)
- Hong Shen
- University of Maryland-Baltimore County, Baltimore, MD, USA
| | | | | | | |
Collapse
|
22
|
Pabst TM, Antos D, Carta G, Ramasubramanyan N, Hunter AK. Protein separations with induced pH gradients using cation-exchange chromatographic columns containing weak acid groups. J Chromatogr A 2008; 1181:83-94. [DOI: 10.1016/j.chroma.2007.12.054] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 12/13/2007] [Accepted: 12/19/2007] [Indexed: 11/26/2022]
|
23
|
Ahrer K, Jungbauer A. Chromatographic and electrophoretic characterization of protein variants. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 841:110-22. [PMID: 16872917 DOI: 10.1016/j.jchromb.2006.05.044] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 05/23/2006] [Accepted: 05/28/2006] [Indexed: 11/17/2022]
Abstract
Almost all proteins are expressed in several variants, also known as isoforms. Individual protein variants differ by modifications of the individual amino acid side chains, or the N- or C-terminus. Typical modifications are glycosylation, phosphorylation, acetylation, methylation, deamidation or oxidation. It is of utmost interest to either get a quantitative picture of the variants of a particular protein or to separate the variants in order to be able to identify their molecular structure. Protein variants are present in native as well as in recombinant proteins. In the case of protein production it is interesting, how variants are generated during fermentation, purification processes, storage, and how present individual variants influence the biological activity. This review provides a comparison of chromatographic and electrophoretic separation methods to analyze and to prepare protein variants.
Collapse
Affiliation(s)
- Karin Ahrer
- Department of Biotechnology, University of Natural Resources and Applied Life Sciences and Austrian Center of Biopharmaceutical Technology, Vienna, Muthgasse 18, A-1190 Vienna, Austria
| | | |
Collapse
|
24
|
Ivanov AV, Kubyshev SS. One-Component eluents for chromatofocusing in weakly basic anionite columns. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2006. [DOI: 10.1134/s0036024406050207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
25
|
Vakstein MS, Nesterenko PN, Ivanov AV, Tessman AB. Single‐Component Eluents for Quasi‐Linear pH Gradients in Weak Cation Exchange Columns. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826070500474071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Maxim S. Vakstein
- a Analytical Chemistry Division, Chemistry Department , M. V. Lomonosov Moscow State University , Lenin Hills , Moscow , Russia
| | - Pavel N. Nesterenko
- a Analytical Chemistry Division, Chemistry Department , M. V. Lomonosov Moscow State University , Lenin Hills , Moscow , Russia
| | - Alexander V. Ivanov
- a Analytical Chemistry Division, Chemistry Department , M. V. Lomonosov Moscow State University , Lenin Hills , Moscow , Russia
| | - Alexey B. Tessman
- a Analytical Chemistry Division, Chemistry Department , M. V. Lomonosov Moscow State University , Lenin Hills , Moscow , Russia
| |
Collapse
|
26
|
Andersen T, Pepaj M, Trones R, Lundanes E, Greibrokk T. Isoelectric point separation of proteins by capillary pH-gradient ion-exchange chromatography. J Chromatogr A 2004; 1025:217-26. [PMID: 14763806 DOI: 10.1016/j.chroma.2003.10.093] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the present work, isoelectric point (pl) separation of proteins by pH-gradient ion-exchange chromatography (IEC) on packed capillary columns is demonstrated. The development of a miniaturized flow-through pH probe for reliable pH monitoring of the column effluent, which was an important technical challenge for adapting this technique to capillary dimensions, was solved by designing a low microliter per minute flow rate housing to a commercially available micro pH probe. Highly linear outlet pH-gradients within the pH range 8.5-4.0 were obtained when applying simple inexpensive buffers consisting solely of piperazine, N-methylpiperazine and imidazole on 10 cm x 0.32 mm i.d. fused silica capillaries packed with anion-exchange poly(styrene divinylbenzene)-based macroporous materials, i.e. 10 microm Mono P from Amersham Biosciences and 10 microm PL-SAX from PolymerLabs. Furthermore, when using a pH-gradient from 6.8 to 4.3, both columns were able to baseline separate the A and B genetic variants of beta-lactoglobulin, which differ with two amino acid residues only, but the PL-SAX column provided almost a two-fold decrease in peak widths compared to the Mono P column. The influence of varying the buffer concentration, injection volume and column temperature on the peak widths and resolution of the beta-lactoglobulins was investigated, e.g. a 100 microl sample of dilute beta-lactoglobulins was injected directly on the column with practically no increase in peak width as compared to what obtained with conventional injection volumes. Finally, a pH-gradient from 6.8 to 4.3 was used to separate proteins in skimmed bovine milk on the PL-SAX column. The milk was simply diluted 1:10 (v/v) with water and filtrated before injection.
Collapse
Affiliation(s)
- Thomas Andersen
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway.
| | | | | | | | | |
Collapse
|
27
|
Abstract
Chromatofocusing using high-performance cation-exchange column packings, as opposed to the more commonly used anion-exchange column packings, is investigated with regard to the performance achieved and the range of applications possible. Linear or convex gradients in the range from pH 2.6 to 9 were formed using a variety of commercially available column packings that provide a buffering capacity in different pH ranges, and either polyampholytes or simple mixtures having a small number (three or fewer) of buffering species as the elution buffer. The resolutions achieved using cation-exchange or anion-exchange chromatofocusing were in general comparable, although for certain pairs of proteins better resolution could be achieved using one type of packing as compared to the other, evidently due to the way electrostatic charges are distributed on the protein surface. Several chromatofocusing methods were investigated that take advantage of the acid-base properties of commercially available cation-exchange column packings. These include the use of gradients with a composite shape, the use of very low pH ranges, and the use of elution buffers containing a single buffering species. The advantages of chromatofocusing over ion-exchange chromatography using a salt gradient at constant pH were illustrated by employing the former method and a cation-exchange column packing to separate beta-lactoglobulins A and B, which is a separation reported to be impossible using the latter method and a cation-exchange column packing. Trends in the apparent isoelectric points determined using cation- and anion-exchange chromatofocusing were interpreted using applicable theories. Results of this study indicate that cation-exchange chromatofocusing is a useful technique which is complementary to anion-exchange chromatofocusing and isoelectric focusing for separating proteins at both the analytical and preparative scales.
Collapse
Affiliation(s)
- Xuezhen Kang
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | | |
Collapse
|
28
|
Shan L, Anderson DJ. Gradient chromatofocusing. versatile pH gradient separation of proteins in ion-exchange HPLC: characterization studies. Anal Chem 2002; 74:5641-9. [PMID: 12433100 DOI: 10.1021/ac020169q] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new chromatofocusing technique called gradient chromatofocusing is characterized. Gradient chromatofocusing generates linear pH gradients on anion-exchange columns with inexpensive low molecular mass buffer components via HPLC gradient mixing. Gradient chromatofocusing results are compared with that of conventional chromatofocusing in the chromatography of several proteins on a Mono P column, including beta-lactoglobulin A and B, ovalbumin, BSA, and conalbumin. Gradient chromatofocusing shows superior performance, with resolution increases greater than 3-fold being realized for the entire protein mixture and up to 25-fold for a particular protein pair. This performance superiority arises from inherent advantages in the gradient chromatofocusing technique in optimizing conditions pertinent to separation, including buffer concentration and pH gradient slope. These resolution gains arise from both increases in separation factor and decreases in peak width achieved with the pH gradient chromatofocusing technique through the manipulation of buffer concentration and the pH gradient profile. Gradient chromatofocusing is also compared with conventional NaCl gradient ion-exchange chromatography using the same Mono P column, demonstrating 3-fold resolution gains, resulting from a 3-fold decrease in peak width. The present work demonstrates the significantly improved performance that gradient chromatofocusing has in protein separations compared to other ion-exchange chromatographic techniques. Mechanisms for the various effects are discussed.
Collapse
Affiliation(s)
- Lian Shan
- Department of Chemistry, Cleveland State University, Ohio 44115, USA
| | | |
Collapse
|
29
|
Kang X, Frey DD. Chromatofocusing using micropellicular column packings with computer-aided design of the elution buffer composition. Anal Chem 2002; 74:1038-45. [PMID: 11924961 DOI: 10.1021/ac0109319] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Micropellicular, anion-exchange column packings are used in chromatofocusing to demonstrate the resolution and speed achieved when proteins are separated under these conditions. Linear or concave pH gradients are produced with simple mixtures containing four or fewer individual buffering species instead of the more commonly used polyampholyte buffers. Computer-aided design methods are demonstrated for selecting the composition of the elution buffer to produce a pH gradient of a desired shape. The method is applied to high-resolution, analytical- and preparative-scale separations involving horse myoglobin, human hemoglobin variants, and bovine carbonic anhydrase. A useful selection of buffering species is described capable of producing pH gradients of a variety of shapes in the range between pH 9.5 and 5.5.
Collapse
Affiliation(s)
- Xuezhen Kang
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, Baltimore, Maryland 21250, USA
| | | |
Collapse
|
30
|
Shan L, Anderson DJ. Effect of buffer concentration on gradient chromatofocusing performance separating protiens on a high-performance DEAE column. J Chromatogr A 2001; 909:191-205. [PMID: 11269519 DOI: 10.1016/s0021-9673(00)01107-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Gradient chromatofocusing is a recently developed chromatographic technique that overcomes the limitations of conventional chromatofocusing. This technique employs a HPLC gradient system and simple low-molecular-mass buffer components to generate linear or other function pH gradients on ion-exchange columns. Results of the present work show a superior separation of beta-lactoglobulin A and B in gradient chromatofocusing compared to salt gradient chromatography using the same DEAE column, with an optimized resolution of 2.3 obtained with gradient chromatofocusing compared to 1.1 obtained with NaCl gradients at constant pH. A significant advantage of the gradient chromatofocusing technique over the conventional chromatofocusing technique is its ability to employ a relatively wide range of buffer concentrations in the mobile phase, the effect of which is studied in the present work. Five proteins (conalbumin, ovalbumin, bovine serum albumin, beta-lactoglobulin A and B) are chromatographed on a DEAE-polymethacrylate HPLC anion-exchange column using the same approximately linear pH gradient profile but different mobile phase buffer concentrations. Results show a significant effect of buffer concentration on peak width, separation factor and resolution. For example, resolution increases from 1.5 to 2.3 in the separation of beta-lactoglobulin A and B when the concentration of each of the components in the 100% elution buffer is increased from 6.25 to 25.0 mM (with the same outlet pH gradient). This separation trend is also seen in the chromatography of ovalbumin from a commercial source, noting a progressive increase in resolution of two peaks in the sample (resolution increased from 0.7 to 2.4) when the concentration of each of the components in the 100% elution buffer is increased from 6.25 to 37.5 mM (same outlet pH gradient). The gains in the resolution are attributed to an increase in the separation factor, since the peak widths are generally noted to also increase with increased buffer concentration. These results point to a significant interplay between buffer concentration and pH, which is not effectively exploited in either conventional chromatofocusing or in conventional ion-exchange chromatographic procedures employing salt gradient elution at constant pH. Gradient chromatofocusing has the ability of optimizing both parameters, thus providing it with unique capabilities in protein separations.
Collapse
Affiliation(s)
- L Shan
- Department of Chemistry, Cleveland State University, OH 44115, USA
| | | |
Collapse
|
31
|
Xie Y, Van de Sandt E, de Weerd T, Wang NH. Purification of adipoyl-7-amino-3-deacetoxycephalosporanic acid from fermentation broth using stepwise elution with a synergistically adsorbed modulator. J Chromatogr A 2001; 908:273-91. [PMID: 11218130 DOI: 10.1016/s0021-9673(00)00997-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Multicomponent adsorption data of a fermentation broth containing adipoyl-7-amino-3-deacetoxycephalosporanic acid (adipoyl-7-ADCA), a cephalosporin precursor for 7-ADCA, and two key impurities, alpha-hydroxyadipoyl-7-ADCA and alpha-aminoadipoyl-7-ADCA were obtained from batch equilibrium and frontal chromatography tests. Amberlite XAD-1600 was chosen as the resin. A rate model was applied to simulate the chromatograms. An alkaline buffer, which by itself has no affinity for the resin, was used as the eluent. The widely used reversed-phase modulator model is inaccurate in explaining the stepwise elution data. A new model, the induced competition model, has been developed to account for apparent retention of the buffer in the presence of adsorbed species. Close agreement between the simulations and the data was achieved with the new model.
Collapse
Affiliation(s)
- Y Xie
- School of Chemical Engineering, Purdue University, West Lafayette, IN 47907-1283, USA
| | | | | | | |
Collapse
|
32
|
Kang X, Bates RC, Frey DD. High-performance chromatofocusing using linear and concave pH gradients formed with simple buffer mixtures. II. Separation of proteins. J Chromatogr A 2000; 890:37-43. [PMID: 10976792 DOI: 10.1016/s0021-9673(00)00573-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The separation of proteins using high-performance chromatofocusing with linear or concave pH gradients formed using simple mixtures of buffering species in the elution buffer is investigated experimentally. The separation achieved is comparable to that using polyampholyte elution buffers with these types of systems. More specifically, protein band widths at one half of the band height in the range between 0.1 and 0.025 pH units were observed, and good resolution was achieved of protein variants differing by a single amino acid residue in separation times of 30 min or less. An especially useful elution buffer is investigated that contains only four buffering species and that produces a linear pH gradient in the range between pH 9.5 and 6.0 when used together with a particular high-performance column packing made specifically for chromatofocusing. This elution buffer and column packing combination is evaluated by using it for the chromatofocusing of equine myoglobin and human hemoglobin variants. Additional applications are described in which a polyethyleneimine derivatized silica column packing and a pH gradient that is concave in shape are used for the separation of proteins in an E. coli cell lysate.
Collapse
Affiliation(s)
- X Kang
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, Baltimore 21250, USA
| | | | | |
Collapse
|
33
|
Bates RC, Kang X, Frey DD. High-performance chromatofocusing using linear and concave pH gradients formed with simple buffer mixtures. I. Effect of buffer composition on the gradient shape. J Chromatogr A 2000; 890:25-36. [PMID: 10976791 DOI: 10.1016/s0021-9673(00)00574-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Numerical calculations together with simplified analytical relations based on local equilibrium theory are used to determine the factors which govern the shape of the gradient formed during chromatofocusing when simple mixtures of buffering species are employed to produce linear or concave pH gradients. The numerical and analytical development is also used to determine the relation between the gradient shape and the buffering capacities of the adsorbed and liquid phases. Experiments which verify the theoretical methods are described where internally generated, retained pH gradients of various shapes are formed using high-performance chromatography columns. The resulting experimental and theoretical basis can be employed as means for the selection of the buffer composition for use in chromatofocusing.
Collapse
Affiliation(s)
- R C Bates
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, Baltimore 21250, USA
| | | | | |
Collapse
|