Present in the aqueous fluid surrounding olfactory sensory dendrites and are thought to aid in the capture and transport of hydrophobic odorants into and through this fluid (By similarity). May function in both olfactory and gustatory systems. Expressed in both gustatory and olfactory systems of larvae and adults. Expressed in antenna, proboscis and larval chemosensory organ. Expressed in five sensilla on each third antennal segment, in the pharyngeal organs and in the dorsal organ, terminal organ and the ventral pits of the third instar larvae. Also expressed in wing and tarsi. Belongs to the PBP/GOBP family.