Hydrogen bonds with π-acceptors in proteins: frequencies and role in stabilizing local 3D structures

• Published in: Journal of molecular biology Vol. 305; no. 3; pp. 535 - 557
• Main Authors: Steiner, Thomas, Koellner, Gertraud
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 19.01.2001
• Subjects: Animals; aromatic hydrogen bonding; Carbon - chemistry; Carbon - metabolism; Crystallography, X-Ray; Databases as Topic; Humans; Hydrogen - chemistry; Hydrogen - metabolism; Hydrogen Bonding; Models, Molecular; protein structure; Protein Structure, Secondary; Proteins - chemistry; Proteins - metabolism; secondary structure; Thermodynamics; Tryptophan - metabolism; Water - chemistry; Water - metabolism; weak polar interactions; secondary structure; protein structure; hydrogen bonding; aromatic hydrogen bonding; weak polar interactions
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1006/jmbi.2000.4301

A comprehensive structural analysis of X—H⋯π hydrogen bonding in proteins is performed based on 592 published high-resolution crystal structures (⩽1.6 Å). All potential donors and acceptors are considerered, including acidic C—H groups. The sample contains 1311 putative X—H⋯π hydrogen bonds with N—H, O—H or S—H donors, that is about one per 10.8 aromatic residues. By far the most efficient π-acceptor is the side-chain of Trp, which accepts one X—H⋯π hydrogen bond per 5.7 residues. The focus of the analysis is on recurrent structural patterns involving regular secondary structure elements. Numerous examples are found where peptide X—H⋯π interactions are functional in stabilization of helix termini, strand ends, strand edges, β-bulges and regular turns. Side-chain X—H⋯π hydrogen bonds are formed in considerable numbers in α-helices and β-sheets. Geometrical data on various types of X—H⋯π hydrogen bonds are given.