This third edition provides new and updated chapters detailing a complete introduction to common and emerging procedures for characterizing the interactions of individual proteins with their natural ligands, drugs or other binding partners. Chapters detail natural substrates, potential drug leads, quantitative understanding of the mechanism of interaction, and different techniques. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and accessible, Protein Ligand Interactions: Methods and Applications, Third Edition serves as an ideal guide for researchers new to the field of biophysical characterization of protein interactions.