This major soluble protein in olfactory sensilla of male moths serves to solubilize the extremely hydrophobic pheromone molecules such as bombykol and to transport pheromone through the aqueous lymph to receptors located on olfactory cilia. Monomer and disulfide-linked dimers. Antenna. 2 electrophoretic alleles are known: fast and slow. The isoform shown here is the fast form. Belongs to the PBP/GOBP family.