Differences in (-)citronellal binding to various odorant receptors

To test the hypothesis that olfactory receptors (ORs) recognize different molecular features of odor molecules termed odotypes, we studied receptor-ligand interactions of two human and two mouse ORs, recognizing (-)citronellal. Structurally similar receptors provide identical binding pockets (OLFR43, OR1A1, and OR1A2), and have comparable EC50 values. Other ORs with lower sequence identity bind (-)citronellal in a different way, leading to different EC50 values. (C) 2007 Elsevier Inc. All rights reserved.