The Three Functional States of Proteins explores how structured proteins, intrinsically disordered proteins, and phase separated proteins contribute to the complexity of cellular life, and offers insights into their roles in both health and disease. It discusses the latest research findings and highlight groundbreaking discoveries and innovative methodologies used to study these protein states. Traditionally, the different states of proteins have been defined based on their structures and functions. However, it is becoming increasingly clear that these criteria alone may not be sufficient to capture the complex and multifaceted properties of these molecules. Definitions based on thermodynamics and kinetics are now recognized as potentially more appropriate for comprehensively understanding protein states. Emerging evidence indicates that under physiological conditions, a majority of proteins possess the capability to exist in and transition between the native, droplet, and amyloid states. These distinct states play crucial roles in various cellular functions, influenced significantly by their physicochemical and structural properties. The book also considers the interactions among these states and discusses how their internal organization as individual molecules, as well as their collective organization as molecular assemblies are stabilized. Furthermore, it examines the processes by which these states are formed and the cellular functions associated with each specific state.

1. The three functional states of proteins: Beyond the classical "lock-and-key" paradigm
2. Ordered proteins and structure-function relationship: Classical view
3. Binding of a substrate ("lock and key") and conformational adaption ("induced fit") are different stages of enzyme action
4. Intrinsically disordered proteins: Functionality of chaos
5. Protein Conformation-based Phenotypic Switching and Implications in the Origin and Evolution of Multicellularity
6. Hybrid proteins: Fusion chimeras and natural wonders
7. Functional protein oligomers
8. Fuzzy complexes
9. SMARTQ: Single Molecule Amyloid fibRil Tracking and Quantification. A method for accurately imaging, tracking and quantifying the growth of individual amyloid fibrils using TIRF
10. Structural Polymorphism in Amyloids - States within Proteins’ Solid-State
11. Liquid-Liquid Phase Separation, Biomolecular Condensates and Membraneless Organelles: A Novel Blueprint of Intracellular Organization
12. Physical principles and molecular interactions underlying protein phase separation
13. Various levels of phase transitions in the protein universe
14. Targeting phase-separated protein states for drug discovery
15. Protein hydrogels: Structure, Characteristics, and Applications
16. Interactions among the three protein states
17. Protein frustration and fuzziness in the three functional states
18. Thermoresponsive intrinsically disordered protein polymers
19. The evolution and exploration of intrinsically disordered and phase-separated protein states
20. Computational modelling of intrinsically disordered and phase separated protein states
21. Molecular dynamics simulations of intrinsically disordered, fuzzy complexes, and phase separated protein states
22. Biological complexity of the phase separated protein states
23. Protein structure-function continuum