Preface xv 1 Introduction 1 2 Preparation of Bioactive Peptides 3 2.1 Introduction 3 2.2 Preparation Methods for Bioactive Peptides 4 2.2.1 Protein Hydrolysis 4 2.2.1.1 Enzymatic Hydrolysis 4 2.

2.1.2 Microbial Fermentation 7 2.2.1.3 Chemical Hydrolysis 8 2.2.2 Chemical Synthesis 8 2.

2.3 Recombinant Expression Technologies 8 2.2.3.1 Genetic Engineering of Fish- Derived Antifreeze Proteins or Peptides 9 2.2.3.2 Genetic Engineering of Insect- Derived Antifreeze Proteins 9 2.

2.3.3 Genetic Engineering of Plant- Derived Antifreeze Proteins 9 2.2.3.4 Chemical Modification 10 2.3 Separation and Purification Techniques of Peptides 10 2.3.

1 Ultrafiltration 11 2.3.2 Ion Exchange Chromatography 12 2.3.3 Gel Filtration Chromatography 12 2.3.4 Reversed- Phase High- Performance Liquid Chromatography 13 2.3.

5 Capillary Electrophoresis 13 2.3.6 Immobilized Metal Affinity Chromatography 13 2.4 Computer- Aided Screening Technologies for Bioactive Peptides 13 References 15 3 Antifreeze Peptides 21 3.1 Introduction 21 3.2 Production and Purification of AFPs 22 3.2.1 Evaluation Methods of Antifreeze Activity 22 3.

2.2 Nanoliter Osmometer 22 3.2.3 Differential Scanning Calorimetry (DSC) 23 3.2.4 Splat- Cooling 24 3.2.5 Low- Field Nuclear Magnetic Resonance (LF- NMR) 25 3.

2.6 Bio- Valuation Model 25 3.2.7 Novel Technology in Utilization of the Evaluation of Antifreeze Activity 26 3.3 Molecular Characteristics and Structure-Function Relationships of AFPs 26 3.4 Action Mechanisms of AFPs 27 3.5 Application Advances of AFPs in Frozen Food Industry 30 3.5.

1 Edible Safety of AFPs 31 3.5.2 Methods of Introducing AFPs into Food Products 31 3.5.3 Application in Frozen Dough 32 3.5.4 Application in Frozen Meat Products 33 3.5.

5 Application in Frozen Fruit and Vegetable Products 34 3.5.6 Application in Dairy Products 34 3.5.7 Application in Cryobiology 35 3.6 Future Direction 36 References 37 4 Antioxidant Peptides 43 4.1 Sources 43 4.1.

1 Marine Resources 43 4.1.2 Meat and By- Products 44 4.1.3 Plant Sources 47 4.1.4 Dairy Products 48 4.2 Evaluation Method of Activity 49 4.

2.1 In vitro Evaluation 49 4.2.1.1 DPPH Radical Scavenging Assay 50 4.2.1.2 ABTS Radical Scavenging Assay 50 4.

2.1.3 Hydroxyl Radical Scavenging Assay 51 4.2.1.4 Superoxide Anions Radical Scavenging Assay 52 4.2.1.

5 Ferric- Reducing Antioxidant Power (FRAP) 52 4.2.1.6 Oxygen Radical Absorption Capacity (ORAC) Method 53 4.2.2 Cellular Antioxidant Effect 54 4.2.3 In vivo Antioxidant Effect 58 4.

3 Mechanism Consideration 64 4.3.1 Mechanisms Underlying Cellular Antioxidant Effects 64 4.3.2 Mechanisms Underlying In Vivo Antioxidant Effects 65 4.3.3 Structure-Activity Relationship 66 4.3.

3.1 Effect of Molecular Weight 66 4.3.3.2 Effect of Amino Acid Composition and Sequence 67 4.3.3.3 Effect of Secondary Structure 68 4.

4 Security Assessment 69 4.4.1 Toxicological Assessment 70 4.4.2 Immunogenicity Assessment 70 4.4.3 Genotoxicity Studies 70 4.4.

4 Bioavailability and Metabolism Studies 70 4.5 Application of Antioxidant Peptides 71 4.5.1 Applications in the Food Sector 71 4.5.2 Applications in the Pharmaceutical Field 73 4.5.2.

1 Anti- Inflammatory and Liver- Protecting Drugs 74 4.5.2.2 Adjuvant Cancer Treatment Drugs 75 4.5.2.3 Anti- Fatigue Drug 76 4.5.

2.4 Drugs for Other Diseases 77 4.5.3 Applications for Skincare 77 4.5.3.1 Anti- Aging Effect 77 4.5.

3.2 Restoration and Conservation 78 4.5.3.3 Whitening and Moisturizing Effect 79 4.6 Limitation and Challenges 80 4.6.1 Preparation Method 80 4.

6.2 Structural and Properties 81 References 82 5 Antimicrobial Peptides 99 5.1 Sources 100 5.1.1 Plant- Derived Antimicrobial Peptides 100 5.1.1.1 Thionins 100 5.

1.1.2 Plant Defensins 101 5.1.1.3 Snakins 102 5.1.1.

4 Hevein- Like Peptides 102 5.1.1.5 Knottin- Type Peptides 104 5.1.2 Animal- Derived AMPs 105 5.1.2.

1 Piscidin- Like Peptides 105 5.1.2.2 Cathelicidins 106 5.1.2.3 Histone- Derived Antimicrobial Effectors 106 5.1.

2.4 Hepcidin Family 106 5.1.2.5 Defensin Superfamily 106 5.1.3 Microbial- Derived Antimicrobial Peptides 106 5.1.

3.1 RPs 107 5.1.3.2 NRPs 111 5.2 Evaluation Method of Activity 116 5.2.1 In Vitro Antimicrobial Activity 117 5.

2.1.1 Agar Diffusion Method 117 5.2.1.2 Turbidimetric Assay Method 118 5.2.1.

3 Viable Cell Count Method 119 5.2.1.4 Microdilution Method 119 5.2.2 In Vitro Antimicrobial Activity 120 5.2.2.

1 Principles of Model Construction 120 5.2.2.2 Inoculation Routes 121 5.2.2.3 Model Identification 121 5.2.

2.4 Common Mouse Models of Bacterial Infection and Experimental Methods 121 5.3 Mechanism Consideration of AMPs 122 5.3.1 Structure- Mechanism Relationship of AMPs 122 5.3.1.1 Constituents of AMPs 123 5.

3.1.2 Molecular Length of AMPs 123 5.3.1.3 Charges of AMPs 123 5.3.1.

4 Hydrophobicity of AMPs 124 5.3.1.5 Secondary Structure of AMPs 124 5.3.1.6 Curvature of AMPs 124 5.3.

2 Mode of Actions of AMPs 125 5.3.2.1 Targeting Cell Wall Biosynthesis 125 5.3.2.2 Targeting Precursors of Peptidoglycan Biosynthesis 129 5.3.

2.3 Blockage of Peptidoglycan Remodeling 132 5.3.3 Inhibition of DNA Gyrase 132 5.3.4 Suppression of Protein Synthesis and Breakdown 133 5.3.4.

1 Interrupting Protein Translation 134 5.3.4.2 Disruption of Protein Post- Translational Modifications 136 5.3.4.3 Dysregulation of Protein Degradation 139 5.3.

5 Destabilization of Cell Membranes 141 5.4 Security Assessment 145 5.4.1 Cytotoxicity of AMPs 145 5.4.2 In Vivo Toxicity of AMPs 145 5.5 Application 146 5.5.

1 Food Preservation 146 5.5.2 Bioactive Food Ingredients 146 5.5.3 Agricultural Applications 148 5.5.4 Animal Feed Additives 149 5.5.

5 Medical Applications 149 5.5.5.1 Antimicrobial Agent 149 5.5.5.2 Wound Healing 150 5.5.

5.3 Other Applications 150 5.6 Limitations and Challenges 151 5.6.1 Chemical Modifications of AMPs 152 5.6.1.1 Lipidation of AMPs 152 5.

6.1.2 Glycosylation of AMPs 153 5.6.1.3 Peptidomimetics 153 5.6.2 Delivery Systems for AMPs 153 5.

6.2.1 Inorganic and Metallic Nanoparticles for AMPs 153 5.6.2.2 Polymeric Nanoparticles for AMPs 154 References 154 6 Metal- Chelating Peptides 165 6.1 Introduction 165 6.2 Preparation 166 6.

2.1 Enzymatic Hydrolysis 168 6.2.2 Microbial Fermentation Method 169 6.2.3 Chemical Synthesis Method 170 6.3 Evaluation Method of Activity 170 6.3.

1 Chelating Capacity Assessment 173 6.3.2 Physiological Stability Assessment 174 6.3.2.1 High- Performance Liquid Chromatography 174 6.3.2.

2 Mass Spectrometry 174 6.3.2.3 Zeta Potential Analysis 175 6.3.2.4 Integration of Techniques for Comprehensive Assessment 175 6.3.

3 Absorption Efficiency Assessment 175 6.3.4 Biological Activity Assessment 176 6.3.4.1 Cell- Based Assays: Osteoblast- Like MC3T3- E1 Cells 176 6.3.4.

2 In Vivo Studies: Animal Models 176 6.3.4.3 Comprehensive Evaluation of MCPs 177 6.4 Chelation Mechanism 178 6.4.1 Chelation Mechanism of Metal- Chelating Peptides 178 6.4.

2 Key Functional Groups in Metal Binding 178 6.4.3 Advanced Techniques for Understanding Binding Modes 178 6.4.4 Specific Chelation Modes of Peptides with Metal Ions 179 6.4.4.1 Coordination Sites and Bond Formation 179 6.

4.4.2 Main Chelation Modes for Marine Peptides 179 6.4.5 Factors Influencing Chelation 179 6.4.5.1 Amino Acid Composition and Sequence 179 6.

4.5.2 Hydrophilicity/Hydrophobicity Balance 180 6.4.5.3 Functional Groups and Metal Ion Chelation 180 6.4.5.

4 Influence of R Groups 180 6.4.5.5 Amino Acids with High Chelation Activity 180 6.4.6 Conclusion 181 6.5 Applications 182 6.5.

1 The Multifaceted Applications of Metal- Chelating Peptides 182 6.5.1.1 Applications in the Food Industry 182 6.5.1.2 Applications in the Pharmaceutical Industry 182 6.5.

1.3 Conclusion and Future Directions 182 References 183 7 Antiaging Peptides 189 7.1 Definition of Aging and Antiaging Peptides 189 7.1.1 Biological Basis of Aging 189 7.1.2 The Rise of Antiaging Peptides 190 7.2 Natural Sources and Synthetic Antiaging Peptides 191 7.

2.1 Natural Antiaging Peptides 191 7.2.1.1 Animal- Derived Antiaging Peptides 191 7.2.1.2 Plant- Derived Antiaging Peptides 193 7.

2.1.3 Microbial- Derived Antiaging Peptides 194 7.2.2 Preparation Method of Natural Antiaging Peptides 194 7.2.3 Engineering Synthetic Peptides 196 7.2.

3.1 Optimization Strategy Based on Computer- Aided Design 196 7.2.3.2 Modification Techniques: Cyclization, D- Amino Acid Substitution, PEGylation 197 7.3 Structural Characteristics of Antiaging Peptides 199 7.4 Mechanism of Action of Antiaging Peptides 201 7.5 Research Methods and Evaluation System of Antiaging Peptides 208 7.

5.1 The Core Method of Antiaging.