Description
Book SynopsisThe definitive guide to the myriad analytical techniques available to scientists involved in biotherapeutics research Analytical Characterization of Biotherapeutics covers all current and emerging analytical tools and techniques used for the characterization of therapeutic proteins and antigen reagents.
Table of ContentsList of Contributors xv
1 Introduction to Biotherapeutics 1
Jennie R. Lill
1.1 Introduction 1
1.2 Types of Biotherapeutics and Manufacturing Systems 2
1.3 Types of Analyses Performed 5
1.4 Future perspectives 6
Acknowledgments 11
References 11
2 Mass Spectrometric Characterization of Recombinant Proteins 15
Corey E. Bakalarski, Wendy Sandoval, and Jennie R. Lill
2.1 Introduction 16
2.1.1 Ionization 16
2.1.1.1 Matrix Assisted Laser Desorption Ionization 17
2.1.1.2 Electrospray Ionization 19
2.1.2 Mass Analyzers for Intact Molecular Weight Measurement of Biotherapeutics 20
2.1.2.1 Time of Flight and Quadrupole Time of Flight Mass Spectrometers 20
2.1.2.2 High‐Resolution Intact Mass Measurement and Native MS 21
2.1.2.3 Ion Mobility Spectrometry 22
2.1.3 Software for the Analysis of Intact Molecular Weight Measurements 24
2.1.4 Separation Devices for the Characterization of Biotherapeutics 25
2.1.4.1 High‐performance Liquid Chromatography 25
2.1.4.2 Capillary Electrophoresis 26
2.1.4.3 Microfluidic Chromatographic Devices 28
2.2 Peptide Mass Fingerprinting 29
2.3 Tandem Mass Spectrometric Characterization of Biomolecules 30
2.3.1 Bottom‐Up MS 33
2.3.2 Proteoinformatic Analysis of Bottom‐Up Proteomic Data Sets 34
2.3.3 Top‐Down MS 36
2.4 Conclusions and Perspectives 37
References 37
3 Characterizing the Termini of Recombinant Proteins 43
Nestor Solis and Christopher M. Overall
3.1 Introduction 44
3.2 Gel Electrophoresis and Edman Sequencing 46
3.3 Mass Spectrometric Approaches for Characterizing True Starts of Proteins 49
3.3.1 Top‐Down Approaches 49
3.3.2 Current Caveats in Mass Spectrometric Identification of Protein Termini 54
3.3.3 Bottom‐up Approaches for Identification of N‐ and C‐Terminal Peptides 55
3.3.4 Amino Terminal Orientated Mass Spectrometry 56
3.3.5 Determining the True Start of Proteins from ATOMS LC‐MS/MS Data 61
3.4 Conclusions 64
References 66
4 Assessing Activity and Conformation of Recombinant Proteins 73
Diego Ellerman, Till Maurer, and Justin M. Scheer
4.1 Introduction 74
4.2 Circular Dichroism 75
4.2.1 Applications of CD 77
4.2.1.1 Thermal Stability Analysis 77
4.2.1.2 Characterization of the Effect of PEGylation 77
4.2.1.3 Formulation and Stability Studies 77
4.2.1.4 Analysis of Biosimilars 78
4.2.2 Technical Improvements 78
4.3 DSC and Isothermal Titration Calorimetry 79
4.3.1 Use of DSC and ITC in Therapeutics Discovery 80
4.3.2 Protein Conjugation 82
4.3.3 Formulation and Stability 82
4.3.4 Analysis of Biosimilars 83
4.4 Hydrogen–Deuterium Exchange–Mass Spectrometry 85
4.4.1 Applications of HDX 86
4.4.1.1 Ligand‐induced Conformational Changes and Mapping Interaction Sites 86
4.4.1.2 Applications in Protein Engineering 86
4.4.1.3 Comparability and Biosimilar Studies 88
4.4.1.4 Formulation and Aggregation Analysis 89
4.4.2 Technical Improvements and Challenges 89
4.5 Nuclear Magnetic Resonance 90
4.5.1 Applications of NMR 92
4.5.1.1 Flexible Proteins 92
4.5.1.2 Mapping Protein–Protein Interactions 93
4.5.1.3 Epitope Mapping 94
4.5.1.4 Protein Dynamics 94
4.5.1.5 Protein Conjugates and Complexes 94
4.5.1.6 Posttranslational Modifications 95
4.5.1.7 Biosimilars 95
4.6 Concluding Remarks 96
References 98
5 Structural Characterization of Recombinant Proteins and Antibodies 111
Paola Di Lello and Patrick Lupardus
5.1 Introduction 112
5.2 Antigens, Epitopes, and Paratopes 113
5.2.1 Rationale for Structural Characterization of Epitopes 113
5.3 Choice of Analytical Method for Epitope Mapping 117
5.3.1 EM for Epitope Analysis 117
5.3.2 Epitope and Paratope Mapping by NMR 118
5.3.2.1 Epitope/Paratope Mapping by Chemical Shift Perturbations 119
5.3.2.2 Final Considerations 122
5.3.3 Epitope Mapping by X‐ray Crystallography 122
5.4 Recombinant Antigen Generation 123
5.4.1 E. coli Expression of Antigens 124
5.4.2 Insect Cell Expression of Antigens 125
5.4.3 Mammalian Expression of Antigens 126
5.5 N‐linked Glycosylation 127
5.5.1 E. coli Expression to Remove Glycosylation as a Factor 128
5.5.2 Manipulating N‐linked Glycans on Antigens 128
5.6 Antibody Generation for Crystallography 129
5.7 Crystallization of Antibody/Antigen Complexes 130
5.8 Conclusion 131
References 131
6 Antibody de novo Sequencing 139
Natalie Castellana and Adrian Guthals
6.1 Introduction 139
6.2 Technical Details on Antibody de novo Sequencing 141
6.2.1 Achieving Complete Protein Coverage 141
6.2.2 Achieving High Sequencing Accuracy 142
6.2.3 Handling Protein Modifications 143
6.2.4 Handling Sample Purity 143
6.3 Bioinformatics Workflow 146
6.3.1 Spectral Preprocessing 146
6.3.2 Spectral Alignment‐based Approach 146
6.3.3 Sequence Homology‐based Approaches 147
6.3.4 Semi‐automated and Manual de novo Sequencing 149
6.4 Sequence Validation 149
6.4.1 Mass Spectrometry‐based Statistics 149
6.4.2 Intact Mass Comparison 150
6.4.3 Synthetic Peptides 150
6.5 Conclusions 150
References 151
7 Characterization of Antibody–Drug Conjugates 155
Yichin Liu
7.1 Introduction 156
7.2 Characterization of DAR Utilizing MS 157
7.2.1 The Stability of Conjugation Chemistry and the Cleavable Linker of ADC 157
7.2.2 Historical Usage of Hydrophobic Interaction Chromatography in ADC Characterization 158
7.2.3 Intact MS Detection under Denaturing Condition 159
7.2.4 Intact MS Characterization under Native Conditions 159
7.2.5 Middle‐down and Bottom‐up MS Approach in Mapping Drug Conjugates 161
7.3 Structural Characterization of ADC 162
7.3.1 Ion‐Mobility Mass Spectrometry 162
7.3.2 Hydrogen–Deuterium Exchange Mass Spectrometry 163
7.4 Characterization of ADC Catabolism by MS 163
7.5 Conclusions 164
References 165
8 Characterization of Bispecific or Other Hybrid Molecules 169
T. Noelle Lombana and Christoph Spiess
8.1 Introduction 170
8.1.1 Bispecific Antibody Applications 170
8.2 Overview of the Various Bispecific Formats 172
8.2.1 Purification from Mixtures 175
8.2.2 Bispecific Antibodies and Alternative Scaffolds with Tethered Domains 176
8.2.3 Bispecific Molecules with Engineered Mutations 177
8.2.4 Native Bispecific IgG with Dual Binding Behavior 178
8.2.5 Bispecific Antibody Conjugates 179
8.3 Alternatives to Bispecific Antibodies: Antibody Mixtures 179
8.4 Characterization of the Bispecific Molecule 180
8.4.1 Characterization by Bioanalytical Methods 180
8.4.2 Characterization by Mass Spectrometry Methods 183
8.4.2.1 General Considerations 183
8.4.2.2 Purity Analysis of the Final Bispecific Antibody 183
8.4.2.3 Antibody Mixtures 184
8.4.2.4 Increasing Resolution 185
8.4.3 Characterization of Bispecific Antibodies by Binding Assays 185
8.4.4 Developability Assessment of the Bispecific Antibody 186
8.4.4.1 Expression 186
8.4.4.2 Physicochemical Properties 187
8.4.4.3 Chemical Modifications 187
8.4.4.4 Characterization of In Vivo Properties 188
8.5 Conclusions 189
References 190
9 Bio‐Repository 199
Anne Baldwin, Kurt Schroeder, Lovejit Singh, and Karen Billeci
9.1 Introduction 199
9.2 Large Molecule Repository Management 202
9.2.1 Informatics 202
9.2.2 Automation 206
9.2.2.1 Automated Refrigerated or Freezer Stores 206
9.2.2.2 Lab Automation 207
9.3 Challenges and Future Perspectives for Working with Diverse Biological Reagent Types 208
References 209
10 Characterization of Residual Host Cell Protein Impurities in Biotherapeutics 211
Denise Krawitz, Jason C. Rouse, Justin B. Sperry, Wendy Sandoval, and Martin Vanderlaan
10.1 Introduction 212
10.2 HCP Measurement and Reporting 212
10.2.1 Antibodies to HCPs 213
10.2.2 Guidance on HCP Limits and Testing 215
10.3 Methods to Characterize Host Cell Impurities 217
10.3.1 HCP‐ELISA 217
10.3.2 SDS‐PAGE and Western Blots 217
10.3.3 MS Methods for HCP Analysis 219
10.3.3.1 Gel Electrophoresis and MALDI or nanoLC‐MS/MS 220
10.3.3.2 Two Dimensional LC‐MS/MS 221
10.3.3.3 Targeted MS Analysis 223
10.3.3.4 Ultrahigh‐Resolution 1D LC‐MS/MS 224
10.3.3.5 Top‐down Proteomics 227
10.4 Use of HCP‐ELISA and Orthogonal
1D LC‐MS/MS in Practice 228
10.4.1 Pros and Cons of MS for Orthogonal HCP Analysis 231
10.4.2 Considerations and MS Evolution 232
10.5 Risk of HCPs Present in Products 232
10.6 Conclusions 233
References 234
11 Analytical Tools for Biologics Molecular Assessment 239
Wilson Phung, Wendy Sandoval, Robert F. Kelley, and Jennie R. Lill
11.1 Introduction to Molecular Assessment 240
11.2 Molecular Assessment 243
11.3 Biotherapeutic Stability 244
11.3.1 Deamidation and Isomerization of Asparagine 246
11.3.2 Oxidation 246
11.4 Physical Degradation 248
11.5 Yield and Structural Stability 249
11.6 Posttranslational Modifications 250
11.7 Analytical Techniques 251
11.8 Summary 252
References 254
12 Glycan Characterization: Determining the Structure, Distribution, and Localization of Glycoprotein Glycans 257
John B. Briggs
12.1 Introduction 258
12.2 Glycan Labeling 264
12.3 Compositional Analysis 266
12.3.1 Neutral Sugar Analysis 267
12.3.2 Sialic Acid Analysis 269
12.4 Glycan Release 272
12.4.1 Release of N‐linked Glycans 272
12.4.2 Release of O‐linked Glycans 274
12.5 Determining Sites of Glycosylation 276
12.5.1 MS‐Based Screening for Glycopeptides 278
12.5.2 Identification of Glycosylation Sites by Analysis of Native Glycopeptides 279
12.5.3 Identification of N‐linked Glycosylation Sites by Enzymatic Labeling of Glycosylation Sites 281
12.5.4 Identification of O‐linked Glycosylation Sites by Chemical Labeling of Glycosylation Sites 283
12.5.5 Identification of Glycosylation Sites by Edman Degradation 285
12.6 Determining N‐linked Glycan Distribution 286
12.6.1 Assessing Glycan Distribution by MS 287
12.6.1.1 Assessing Glycan Distribution by Mass Spectrometric Analysis of Glycoproteins 287
12.6.1.2 Assessing Glycan Distribution by Mass Spectrometric Analysis of Glycopeptides 294
12.6.1.3 Determining Glycan Distribution by Mass Spectrometric Analysis of Native Glycans 294
12.6.1.4 Determining Glycan Distribution by Mass Spectrometric Analysis of Derivatized Glycans 298
12.6.2 Assessing Glycan Distribution by Chromatography and CE 300
12.6.2.1 Analysis of N‐linked Glycans by CE 300
12.6.2.2 Analysis of N‐linked Glycans by HILIC 303
12.6.2.3 Determining Glycan Distribution by HPAEC 305
12.7 Comparison of Methods Used in Determining Glycan Distribution 307
12.8 Assessing N‐linked Glycan Structure 309
12.8.1 Characterization of Glycan Structure Using Standards and Enzymatic Studies 309
12.8.2 Characterization of Glycan Linkage by Methylation Analysis 310
12.8.3 Characterization of Glycan Structure by MS2 312
12.8.4 Characterization of Glycan Structure by NMR 317
References 320
Index 333
