Peptides as Drugs: Discovery and Development

Peptides as Drugs......Page 5
Contents......Page 7
Preface......Page 13
List of Contributors......Page 15
1.1 Discovery of New Potential Drug Targets and the Limitations of Druggability......Page 19
1.2 Protein Interaction Domains Are at the Core of Signaling Pathways......Page 22
1.3 Peptides as Inhibitors of Protein Interactions......Page 23
References......Page 25
2.2 The Cytokines......Page 27
2.2.1 The Receptors......Page 29
2.2.2 “Simple” Receptors......Page 30
2.2.3 “Complex” Receptors......Page 31
2.3 Defining Receptor Recognition Sites in Cytokines Using Chimeric Proteins......Page 33
2.4 Receptor Recognition Sites are Organized as Exchangeable Modules......Page 35
2.5 The Concept of Fusing the Cytokine to the Soluble Receptor: Hyper-IL-6......Page 37
2.6 Antagonists Specifically Inhibiting IL-6 Trans-Signaling......Page 38
2.7 In Vitro Evolution of Peptides and Proteins......Page 40
2.7.1 Platforms for the Selection of High-Affinity Binders......Page 42
2.7.2 Agonists and Antagonists of Cytokines and Growth Hormones......Page 45
2.8 Concluding Remarks......Page 46
References......Page 47
3.1 Introduction......Page 53
3.2 CD44 Proteins and Their Involvement in RTK Activation......Page 54
3.3 CD44v6 Acts as a Coreceptor for c-Met and Ron......Page 55
3.4 Three Amino Acids in CD44 Exon v6 Are Crucial for the CD44v6 Coreceptor Function, and Small Peptides Can Interfere with This Function......Page 56
3.5 The Ectodomain of CD44v6 Binds to HGF......Page 60
3.6 Peptides Corresponding to Exon v6 of CD44 Inhibit Metastatic Spread of Tumor Cells......Page 61
3.7 The Significance of the Collaboration between CD44v6 and c-Met In Vivo......Page 63
3.8 The CD44v6 Peptides Interfere with Angiogenesis......Page 64
3.9 Outlook......Page 66
References......Page 67
4.1 Human Papillomaviruses and Oncogenesis......Page 75
4.1.1 Cervical Cancer......Page 76
4.1.2 The E6 and E7 Genes......Page 77
4.2 Peptide Aptamers Targeting the HPV E6 Oncoprotein......Page 79
4.3.1 Therapeutic Target Protein Evaluation by Peptide Aptamers......Page 82
4.3.2 The Intrinsic Therapeutic Potential of Peptide Aptamers......Page 83
4.3.3 Identification of Functional Peptide Mimics by Displacement Screening......Page 85
4.4 Perspectives......Page 86
References......Page 87
5.1 Introduction: The Potential of Peptides as Drugs in the Treatment of HIV Infection......Page 91
5.2 The HIV Entry Process......Page 93
5.3.1.1 Defensins......Page 95
5.3.2 Chemokines......Page 96
5.3.3 Synthetic Peptides and Peptidomimetics......Page 97
5.4 Inhibitors of the Viral and Cellular Membrane Fusion Process......Page 99
5.5 Entry Inhibitory Peptides Selected by the Phage Display Technology......Page 101
5.6 Limitations of Peptides in the Treatment of HIV Infection......Page 102
5.7 Strategies to Prolong the In Vivo Half-Life of Antiviral Peptides......Page 103
5.8 Antiviral Peptides in Gene Therapy of HIV Infection......Page 106
References......Page 111
6.2 Peptide Design and Expression Cassettes......Page 121
6.3 Stable Delivery and Expression of Peptides: Gamma-Retro- and Lentiviral Vectors......Page 124
6.4 Gamma-Retroviral Vectors......Page 127
6.5 Lentiviral Peptide Delivery......Page 129
6.6 Vectors for Transient Expression of Peptides: Adenoviruses and Adeno-Associated Viruses......Page 132
6.7 Perspective......Page 137
References......Page 138
7.2 Discovery and Classification of CPPs......Page 143
7.3 Internalization Mechanisms of Cell-Penetrating Peptides......Page 144
7.4 Models of CPP Uptake......Page 146
7.5 The Current View of CPP Uptake......Page 147
7.6 CPPs as Cargo Delivery Vehicles......Page 148
7.9 Delivery of Oligonucleotides......Page 149
7.10 Cytotoxicity of Cell-Penetrating Peptides......Page 151
7.11 In Vivo Drug Delivery with CPPs......Page 152
7.13 Conclusions......Page 154
References......Page 155
8.1 Introduction......Page 163
8.2 Protein Production......Page 164
8.2.1 Bacterial Systems......Page 166
8.2.2 Yeast Systems......Page 168
8.2.3 Baculovirus Systems......Page 170
8.2.4 Chemical Synthesis......Page 171
8.3.1 Ammonium Sulfate Fractionation......Page 172
8.3.2 Affinity Chromatography......Page 173
8.3.5 Hydrophobic Interaction Chromatography......Page 174
8.4.1 Correct Refolding versus Aggregation......Page 175
8.4.2 Techniques for Protein Folding......Page 176
8.4.3 Factors Influencing Refolding......Page 177
8.5.1 Properties and Requirements of Scaffolds......Page 179
8.6 The Use of Cell-Penetrating Peptides for Cellular Uptake of Purified Proteins......Page 180
8.6.1 Uptake of Proteins by Lipid Raft-Dependent Macropinocytosis......Page 182
8.6.2 Points of Consideration for the Use of CPPs......Page 183
8.7.1 Bioactive Peptides......Page 185
8.7.2 Peptide Aptamers......Page 186
8.7.3 Designed Peptides......Page 189
8.8.1 Extracellular Protein Therapeutics and Peptides with Extracellular Targets......Page 190
8.8.2 Peptides Targeting Intracellular Targets In Vivo......Page 191
8.9 Concluding Remarks......Page 193
References......Page 194
9.1 Introduction......Page 205
9.2.1 Fmoc-Based Synthesis of Peptides on Cellulose Membranes......Page 206
9.2.2 Fabrication of CelluSpots......Page 208
9.2.5 Generation of Peptide Arrays by Chemoselective Immobilization......Page 209
9.3.1 Generation of Small Amounts of Soluble Peptide Libraries......Page 211
9.3.2 Epitope Mapping of Monoclonal Antibodies......Page 212
9.3.3 Investigation of Antibody Epitopes in Polyclonal Sera......Page 213
9.3.4.1 General Considerations......Page 214
9.3.4.2 Identification of Enzyme Substrates......Page 215
9.3.6 Screening for Antimicrobial Peptides......Page 220
9.3.8 Identification of Metal Ion-Selective Peptides......Page 222
9.4 Challenges in High-Throughput Screening (HTS)......Page 223
9.5 Future Perspectives......Page 224
References......Page 225
Index......Page 237