Key residues involved in the interaction between Cydia pomonella pheromone binding protein 1 (CpomPBP1) and Codlemone.

Codlemone exhibited high affinity to CpomPBP1, studying their binding mode can provide insights into the rational design of active semiochemicals. Our findings suggested that residues including Phe12, Phe36, Trp37, Ile52, Ile 94, Ala115 and Phe118 were favorable to the binding of Codlemone to CpomPBP1, whereas residues providing unfavorable contributions like Ser56 were negative to the binding. Van der waals energy and electrostatic energy, mainly derived from the sidechains of favorable residues, contributed most in the formation and stability keeping of CpomPBP1-Codlemone complex. Of the residues involved in the interaction between CpomPBP1 and Codlemone, Phe12 and Trp37, whose mutation into Ala caused significant decrease of CpomPBP1 binding ability, were two key residues in determining the binding affinity of Codlemone to CpomPBP1. This study shed lights on discovering novel active semiochemicals as well as facilitating chemical modification of lead semiochemicals.