Exploring the Molecular Space of Bitter Peptides via Sensory, Receptor, and Sequence Data

This study explores the chemical space of bitter peptides through a curated data set, named Bitter Peptide Space (BPS)-1000, which includes experimentally validated bitter and nonbitter peptides. The data set integrates sensory data, bitter taste thresholds (BTTs), and bitter taste receptor (TAS2R) activity when available. The inclusion of modified peptides further expands the data set’s diversity. The HELM (Hierarchical Editing Language for Macromolecules) and BILN (Boehringer Ingelheim Line Notation) notations have been generated to provide a unique representation for both canonical and modified peptides. Through sequence-based and structure-based analyses, the study highlights the role of hydrophobicity, molecular size, and specific amino acid composition in the bitter and nonbitter sets in canonical and modified peptides, suggesting differences that could contribute to bitterness and enhancing the understanding of bitter peptide characteristics.