A pheromone-binding protein from the cockroach Leucophaea maderae: cloning, expression and pheromone binding

Area of Science:

• Insect olfaction and chemoreception
• Molecular biology and protein biochemistry

Background:

• Odorant-binding proteins (OBPs) facilitate volatile compound transport to olfactory receptors in insect sensilla.
• Pheromone-binding proteins (PBPs), a subgroup of OBPs, are crucial for sexual pheromone perception.
• OBP presence was previously documented only in Endopterygota and Paraneoptera, with hypothesized but unconfirmed expression in Orthopteroids.

Purpose of the Study:

• To describe the first OBP from a Dictyopteran insect, Leucophaea maderae.
• To characterize the binding affinity of this OBP for specific pheromonal compounds.

Main Methods:

• Identification and characterization of a PBP from Leucophaea maderae (PBPLma).
• Expression of recombinant PBPLma in Escherichia coli.
• Binding assays using fluorescence displacement of 8-anilino-1-naphtalenesulphonic acid (ANS).

Main Results:

• PBPLma exhibits characteristics typical of the OBP family.
• PBPLma is specifically expressed in the antennae of adult female L. maderae.
• PBPLma selectively binds 3-hydroxy-butan-2-one and butane-2,3-diol, but not E-2-octenoic acid, senecioic acid, or other alkyl volatiles.

Conclusions:

• This study provides the first evidence of OBP expression in Dictyoptera.
• PBPLma demonstrates selective binding, suggesting a filtering mechanism for pheromone perception in L. maderae.
• The findings contribute to understanding the evolution and function of OBPs in insect chemoreception.