The insect attractant 1-octen-3-ol is the natural ligand of bovine odorant-binding protein.
Bovine odorant-binding protein (bOBP) is a dimeric lipocalin present in large amounts in the respiratory and olfactory nasal mucosa. The structure of bOBP refined at 2.0-A resolution revealed an elongated volume of electron density inside each buried cavity, indicating the presence of one (or several) naturally occurring copurified ligand(s) (Tegoni et al. (1996) Nat. Struct. Biol. 3, 863-867; Bianchet et al. (1996) Nat. Struct. Biol. 3, 934-939). In the present work, by combining mass spectrometry, x-ray crystallography (1.8-A resolution), and fluorescence, it has been unambiguously established that natural bOBP contains the racemic form of 1-octen-3-ol. This volatile substance is a typical component of bovine breath and in general of odorous body emanations of humans and animals. The compound 1-octen-3-ol is also an extremely potent olfactory attractant for many insect species, including some parasite vectors like Anopheles (Plasmodium) or Glossina (Trypanosoma). For the first time, a function can be assigned to an OBP, with a possible role of bOBP in the ecological relationships between bovine and insect species.
Ramoni
R
R
Architecture et Fonction des Macromolécules Biologiques, Unité Mixte de Recherche 6098, CNRS and Universités Aix-Marseille I and II, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. vetbioc@unipr.it
Vincent
F
F
Grolli
S
S
Conti
V
V
Malosse
C
C
Boyer
F D
FD
Nagnan-Le Meillour
P
P
Spinelli
S
S
Cambillau
C
C
Tegoni
M
M
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D007313:Insecta; D007700:Kinetics; D008024:Ligands; D013058:Mass Spectrometry; D008958:Models, Molecular; D000442:Octanols / Q000737:chemistry* / Q000378:metabolism*; D018035:Receptors, Odorant / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology; D013050:Spectrometry, Fluorescence
D005456:Fluorescent Dyes; D008024:Ligands; D000442:Octanols; D018035:Receptors, Odorant; C045648:odorant-binding protein; C038844:1-octen-3-ol