This book focuses on thielocin B1 (TB1), which was found to be an inhibitor of protein–protein interactions (PPIs) of proteasome assembling chaperone (PAC) 3 homodimer, and elucidates the mechanism by nuclear magnetic resonance (NMR) studies. Interfaces of PPIs recently have been expected to be novel therapeutic targets, while it is difficult to apply conventional methodology based on lock an…