A structural role for tryptophan in proteins, and the ubiquitous Trp C^δ1-H...O=C (backbone) hydrogen bond.

ABSTRACT: Tryptophan is the most prominent amino acid found in proteins, with multiple functional roles. Its side chain is made up of the hydrophobic indole moiety, with two groups that act as donors in hydrogen bonds: the N^ϵ-H group, which is a potent donor in canonical hydrogen bonds, and a polarized C^δ1-H group, which is capable of forming weaker, noncanonical hydrogen bonds. Due to adjacent electron-withdrawing moieties, C-H...O hydrogen bonds are ubiquitous in macromolecules, albeit contingent on the polarization of the donor C-H group. Consequently, C^α-H groups (adjacent to the carbonyl and amino groups of flanking peptide bonds), as well as the C^ϵ1-H and C^δ2-H groups of histidines (adjacent to imidazole N atoms), are known to serve as don

SUBMITTER: Szczygiel M 

PROVIDER: S-EPMC11220837 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature