Selective and pH-dependent binding of a moth pheromone to a pheromone-binding protein.
Fluorescence and circular dichroism (CD) data suggest that the major pheromone-binding protein (PBP) from the wild silkmoth, Antheraea polyphemus, ApolPBP1, undergoes a pH-dependent conformational change similar to that previously observed for the PBP from the silkworm moth, Bombyx mori, BmorPBP. All three constituents of the sex pheromone, E6,Z11-16Ac, E6,Z11-16Ald, and E4,Z9-14Ac, bound to ApolPBP1 with apparent high affinity at high pH, but reduced binding at low pH when tested individually in a "cold binding assay." In competitive assays, however, ApolPBP1 showed considerable preference for the major constituent of the sex pheromone, E6,Z11-16Ac. These data suggest that specificity of PBPs contributes at least in part to the remarkable selectivity of moth's olfactory system.
Leal
Walter S
WS
Maeda-Duffey Laboratory, Department of Entomology, University of California, Davis, CA 95616, USA. wsleal@ucdavis.edu
Chen
Angela M
AM
Erickson
Melissa L
ML
D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins; D009036:Moths / Q000737:chemistry* / Q000378:metabolism; D010675:Pheromones / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D013050:Spectrometry, Fluorescence
D002352:Carrier Proteins; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010675:Pheromones; C403094:pheromone-binding protein, Bombyx