Sweet, umami and bitter taste receptors: State of the art of in silico molecular modeling approaches

The human taste experience is the result of five basic taste qualities, namely sweet, salty, bitter, sour and umami. Sweet, bitter, and umami are mediated by G protein-coupled receptors (GPCRs), whereas sour and salt are modulated by specialized membrane channels. Taste perception starts with the interaction between a taste-active molecule (substance) and a specialized receptor located on the taste buds at the level of the cell membrane. Once the interaction has occurred, taste receptor cells are able to transduce the information content of the chemical stimulus into nerve signals directly to the brain. Therefore, the receptor-mediated recognition of taste molecules is the first episode leading to taste perception. In this review, we provide a complete overview of in silico molecular modeling techniques applied to the study of umami, sweet, and bitter taste receptors. Structure-based computational tools, usually applied to investigate the binding mode of bioactive molecules into their targets and to rationally design new drug molecules, are proven equally useful in the field of chemical senses to shed light on the molecular acknowledgment of tastants. The recent computational advancements in the taste research field, and particularly the computation-driven investigations of the tastant-receptor binding, provided a better understanding of the molecular mechanisms underlying food tastants’ sensing and could have an impressive contribution to the identification of new taste modulators in the future.