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Pheromone-binding proteins (PBPs) play a significant role in olfaction and mating. The present work was designed to isolate, extract, and purify the pheromone-binding proteins from the antennae of male Chilo partellus (Swinhoe, 1885) (Lepidoptera: Crambidae). The pheromone-binding proteins extracted from the male antennae were found to be 770 μg in 100 mg of sample. Pheromone-binding protein molecular weight was determined as 17 kDa by SDS-PAGE analysis. Identified proteins were purified through gel extraction with a recovery percentage of proteins up to 95%. Purified protein samples are analyzed on native PAGE gels. Relative mobility of proteins was determined as 0.574 nm in the densitometry analysis. These identified pheromone-binding proteins can be used for identification of novel pheromone compounds in in vitro studies. This study can be helpful in designing integrated pest management programs to control the maize stem borer by mass trapping of male moths. [ABSTRACT FROM AUTHOR]

Pheromone-binding proteins (PBPs) are thought to contribute to the specificity of the pheromone detection system through an initial selective binding with pheromone molecules. Here, we report different expression levels of PBP transcripts in the antennae of two populations of the stemborer Sesamia nonagrioides (Lepidoptera: Noctuidae), one collected in Europe and one in sub-Saharan Africa. The three PBP transcripts previously identified in this species were found to be expressed in both male and female antennae. Whereas PBP3 did not show any differential expression, PBP1 and PBP2 appeared to be expressed differently according to the population origin and sex. Simultaneously, we measured and compared the ratio of the three components of the S. nonagrioides pheromone blend (Z11-16:Ac; Z11-16:OH; Z11-16:Ald) in females of the two populations. The ratio of Z11-16:OH and Z11-16:Ald varied significantly according to the population origin of this species. Cluster analyses revealed similar differentiation patterns between PBP1 and PBP2 expression levels and the ratios of Z11-16:OH and Z11-16:Ald. Different female sexual signals may thus correspond to different male reception systems, which are adjusted by the PBP expression levels, thereby ensuring optimal communication within populations. [ABSTRACT FROM AUTHOR]

Binding properties of six heterologously expressed pheromone-binding proteins (PBPs) identified in the silkmoths Antheraea polyphemus and Antheraea pernyi were studied using tritium-labelled pheromone components, (E,Z)-6,11-hexadecadienyl acetate (3H-Ac1) and (E,Z)-6,11-hexadecadienal (3H-Ald), common to both species. In addition, a known ligand of PBP and inhibitor of pheromone receptor cells, the tritium-labelled esterase inhibitor decyl-thio-1,1,1-trifluoropropanone (3H-DTFP), was tested. The binding of ligands was measured after native gel electrophoresis and cutting gel slices. In both species, PBP1 and PBP3 showed binding of 3H-Ac1. In competition experiments with 3H-Ac1 and the third unlabelled pheromone component, (E,Z)-4,9-tetradecadienyl acetate (Ac2), the PBP1 showed preferential binding of Ac1, whereas PBP3 preferentially bound Ac2. The PBP2 of both species bound 3H-Ald only. All of the six PBPs strongly bound 3H-DTFP. Among unlabelled pheromone derivatives, alcohols were revealed to be the best competitors for 3H-Ac1 and 3H-Ald bound to PBPs. No pH influence was found for 3H-Ac1 binding to, or its release from, the PBP3 of A. polyphemus and A. pernyi between pH 4.0 and pH 7.5. The data indicate binding preference of each of the three PBP-subtypes (1–3) for a specific pheromone component and support the idea that PBPs contribute to odour discrimination, although to a smaller extent than receptor activation. [ABSTRACT FROM AUTHOR]