Virtual Screening of Plant Volatile Compounds Reveals a High Affinity ofHylamorpha elegans(Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host

Abstract

Hylamorpha elegans (Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs in H. elegans as well as six new volatiles released by its native host Nothofagus obliqua (Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. obliqua revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies.

Exploring the Potentiality of Natural Products from Essential Oils as Inhibitors of Odorant-Binding Proteins: A Structure- and Ligand-Based Virtual Screening Approach To Find Novel Mosquito Repellents

“…It is also worth noting that a previous study obtained similar results using docking energies for DEET (Δ G = −5.86 kcal mol –1 ; K i = 50.51 μM) and potential repellents of Agam OBP1, such as 2-methyl-1-(1-oxodecyl)piperidine (Δ G = −7.36 kcal mol –1 ; K i = 4.04 μM), 1-(1-oxoundecyl)piperidine (Δ G = −7.20 kcal mol –1 ; K i = 5.28 μM), and N , N -diethyl-3-phenylpropanamide (Δ G = −6.49 kcal mol –1 ; K i = 17.21 μM). 39 Similarly, a previous study performed binding free energy calculations using the MM/GBSA method for β-caryophyllene (sesquiterpene), β-myrcene (monoterpene), and cis -β-ocimene (monoterpene) complexed to different OBP classes of Hydroides elegans , and their energy values approximated our calculated values of OBP1, 13 which is also consistent with the inhibitory activity.…”

“…Several studies have reported the specific inhibitory activity of some NPs from essential oil against insect OBPs with satisfactory binding affinity, such as sesquiterpenes (e.g., benzaldehyde, β-myrcene, and α-copaene) 13 and alcohols (e.g., n -decanol and n -dodecanol). 12 In the present study, we identified that predominantly monoterpenoids, such as p -cymen-8-yl, thymol acetate, and carvacryl acetate, mimic the binding mode of DEET, exhibiting similar pharmacophoric groups and intermolecular interactions with the protein pocket, which sheds light on the molecular mechanism of action of these compounds against olfactory recognition of insects, reinforcing the previous experimental repellency studies for this chemical class.…”

An Antennae-Specific Odorant-Binding Protein Is Involved in Bactrocera dorsalis Olfaction

“…Based on these previous researches, it is possible to conclude that the OBPs we identify within our current study (i.e., those that are expressed in nonolfactory tissues) may have other physiological or chemosensory functions. Here we propose that these proteins may participate in other chemosensory functions, such as the modulation of gustation, as opposed to (or in conjunction with) any role in olfaction (Blomquist and Vogt, 2003;Leal, 2005;Ling et al, 2014;Gonzalez-Gonzalez et al, 2016;Zhu et al, 2016). The additional OBPs we identify that are abundantly or specifically expressed in the B. dorsalis head may also function in olfaction because the maxillary palps were not explicitly removed in our experiments.…”

Sex- and tissue-specific expression of odorant-binding proteins and chemosensory proteins in adults of the scarab beetle Hylamorpha elegans (Burmeister) (Coleoptera: Scarabaeidae)

“…Although the chemical communication of the species has been studied, and the ability of males to perceive receptive females was reported (Quiroz et al, 2007) , very little is known about the molecular basis of H. elegans olfaction and chemical communication. However, a recent report revealed an olfactory protein linked to the ability to perceive volatiles commonly used in chemical communication by Scarabaeidae species (Venthur et al, 2014; González-González et al, 2016), which suggests that a similar mechanism could be involved in chemical communication in H. elegans .…”