An odorant-binding protein facilitates odorant transfer from air to hydrophilic surroundings in the blowfly.
Chemical sense-related lipophilic ligand-binding protein (CRLBP) is an insect odorant-binding protein (OBP) found abundantly in the taste and olfactory organs of the blowfly, Phormia regina. Through computational construction, a three-dimensional molecular model of a CRLBP indicated good fitting to a fluorescent ligand, 7-hydroxycoumarin (7-HC), in its ligand-binding pocket. By showing that the fluorescence of 7-HC bound to CRLBP migrated in a native electrophoresis gel, we confirmed that CRLBP formed a stable complex with 7-HC. In an odorant-binding experiment, 7-HC vapor odor was introduced by aeration to the aquatic solution containing CRLBP and its binding to CRLBP fluorospectrometrically quantified. Because olfactory organs as well as taste organs of flies respond to vapors, we suggest that CRLBP effectively transfers odorants from the air into aquatic surroundings by forming stable complexes with airborne molecules in both chemosensory organs.
Tsuchihara
Kazuko
K
Human Information Systems, Kanazawa Institute of Technology, 3-1 Yakkaho, Hakusan, Ishikawa 924-0834, Japan.
Fujikawa
Kazuyo
K
Ishiguro
Masaji
M
Yamada
Takuji
T
Tada
Chiyo
C
Ozaki
Koichi
K
Ozaki
Mamiko
M
D000388:Air; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000502:physiology; D004175:Diptera; D019476:Insect Proteins / Q000737:chemistry / Q000502:physiology; D008958:Models, Molecular; D009812:Odorants; D011485:Protein Binding; D018035:Receptors, Odorant / Q000737:chemistry* / Q000502:physiology; D012996:Solutions; D014468:Umbelliferones / Q000737:chemistry; D014867:Water
C094436:CRLBP protein, Phormia regina; D002352:Carrier Proteins; D019476:Insect Proteins; D018035:Receptors, Odorant; D012996:Solutions; D014468:Umbelliferones; C045648:odorant-binding protein; D014867:Water; C031477:7-hydroxycoumarin