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Olaleye O, Graf C, Spanov B, Govorukhina N, Groves MR, van de Merbel NC, Bischoff R. Determination of Binding Sites on Trastuzumab and Pertuzumab to Selective Affimers Using Hydrogen-Deuterium Exchange Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:775-783. [PMID: 36960982 PMCID: PMC10080681 DOI: 10.1021/jasms.3c00069] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/10/2023] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
Hydrogen-deuterium exchange mass spectrometry (HDX-MS) is a method to probe the solvent accessibility and conformational dynamics of a protein or a protein-ligand complex with respect to exchangeable amide hydrogens. Here, we present the application of HDX-MS to determine the binding sites of Affimer reagents to the monoclonal antibodies trastuzumab and pertuzumab, respectively. Intact and subunit level HDX-MS analysis of antibody-affimer complexes showed significant protection from HDX in the antibody Fab region upon affimer binding. Bottom-up HDX-MS experiments including online pepsin digestion revealed that the binding sites of the affimer reagents were mainly located in the complementarity-determining region (CDR) 2 of the heavy chain of the respective antibodies. Three-dimensional models of the binding interaction between the affimer reagents and the antibodies were built by homology modeling and molecular docking based on the HDX data.
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Affiliation(s)
- Oladapo Olaleye
- Analytical
Biochemistry, Department of Pharmacy, University
of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Christian Graf
- Novartis
Technical Research & Development Biologics, Hexal AG, Keltenring
1 + 3, 82041 Oberhaching, Germany
| | - Baubek Spanov
- Analytical
Biochemistry, Department of Pharmacy, University
of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Natalia Govorukhina
- Analytical
Biochemistry, Department of Pharmacy, University
of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Matthew R. Groves
- Drug
Design, Department of Pharmacy, University
of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Nico C. van de Merbel
- Analytical
Biochemistry, Department of Pharmacy, University
of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
- ICON
Bioanalytical Laboratories, Amerikaweg 18, 9407 TK Assen, The Netherlands
| | - Rainer Bischoff
- Analytical
Biochemistry, Department of Pharmacy, University
of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
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2
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Spanov B, Baartmans B, Olaleye O, Nicolardi S, Govorukhina N, Wuhrer M, van de Merbel NC, Bischoff R. Revealing charge heterogeneity of stressed trastuzumab at the subunit level. Anal Bioanal Chem 2023; 415:1505-1513. [PMID: 36693954 PMCID: PMC9974696 DOI: 10.1007/s00216-023-04547-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/24/2022] [Accepted: 01/16/2023] [Indexed: 01/26/2023]
Abstract
Trastuzumab is known to be heterogeneous in terms of charge. Stressing trastuzumab under physiological conditions (pH 7.4 and 37 °C) increases charge heterogeneity further. Separation of charge variants of stressed trastuzumab at the intact protein level is challenging due to increasing complexity making it difficult to obtain pure charge variants for further characterization. Here we report an approach for revealing charge heterogeneity of stressed trastuzumab at the subunit level by pH gradient cation-exchange chromatography. Trastuzumab subunits were generated after limited proteolytic cleavage with papain, IdeS, and GingisKHAN®. The basic pI of Fab and F(ab)2 fragments allowed to use the same pH gradient for intact protein and subunit level analysis. Baseline separation of Fab subunits was obtained after GingisKHAN® and papain digestion and the corresponding modifications were determined by LC-MS/MS peptide mapping and middle-down MALDI-ISD FT-ICR MS. The described approach allows a comprehensive charge variant analysis of therapeutic antibodies that have two or more modification sites in the Fab region.
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Affiliation(s)
- Baubek Spanov
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Bas Baartmans
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Oladapo Olaleye
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Simone Nicolardi
- Center for Proteomics and Metabolomics, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Natalia Govorukhina
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Manfred Wuhrer
- Center for Proteomics and Metabolomics, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Nico C van de Merbel
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV, Groningen, The Netherlands.,Bioanalytical Laboratory, ICON, Amerikaweg 18, 9407 TK, Assen, The Netherlands
| | - Rainer Bischoff
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
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