A team of American scientists from Duke University and the University of California have created artificial olfactory receptors (ORs) to reveal the molecular basis of odor recognition. The study was published in the scientific journal Nature.
Vertebrates perceive odors through G protein-coupled olfactory receptors. Humans have about 400 of these receptors, which allow us to distinguish between pleasant and unpleasant odors.
The OR family consists of two main classes. Class I OPs are tuned to carboxylic acids, picking up the odors of vinegar, spoiled milk, sweat, some cheeses, animal fats and some cooking oils. Class II OPs respond to a wide range of odorants and represent the majority of the human sense of smell.
The ORs the scientists created were genetically modeled after 17 major subfamilies of human ORs, providing templates for individual native ORs with a high degree of sequence and structural similarity.
By comparing the responses of engineered ORs to different odorants (odorant compounds), the study revealed different odorant binding modes and activation mechanisms between class I and class II ORs.
The new approach overcame the main barrier that researchers faced in uncovering the molecular recognition of odorants by the OR family, the authors of the experiment noted.
