The importance of extended conformations and, in particular, the P II conformation for the molecular recognition of peptides

Crystallographic, isotopic labeling nmr and transferred nuclear Overhauser effect studies have highlighted the extended conformation as a very important element of secondary structure at the binding site of many peptide/protein complexes including peptide inhibitors–enzymes, B‐cell epitopes–antibodies, and T‐cell epitopes–major histocompatibility complex (MHC) of class I and II complexes. This paper discusses the peptide ligand conformation consequences of these findings particularly in view of the identification of the P II conformation (left‐handed extended polyproline II) in free solution. © 1994 John Wiley & Sons, Inc.