Odorant binding protein

Odorant binding proteins are abundant small soluble proteins secreted in the nasal mucus of many animal species and in the sensillar lymph of chemosensory sensilla of insects. These proteins were initially identified on the basis of their ability to bind with moderate affinity radioactively labeled odorants (Pelosi et al., 1982). Based on the generally hydrophobic nature of odorant molecules, odorant binding proteins were initially assigned the function of odorant molecule's carriers through the aqueous nasal mucus covering the olfactory epithelium. Extensive research in the last two decades have extended the range of their putative function, however, the precise physiological role of these proteins still remains elusive.  

References

• Pelosi P, Baldaccini NE, Pisanelli AM. Identification of a specific olfactory receptor for 2-isobutyl-3-methoxypyrazine. Biochem J. 1982 Jan 1;201(1):245-8 PMID 7082286