In silico annotation of unreviewed acetylcholinesterase (AChE) in some lepidopteran insect pest species reveals the causes of insecticide resistance

Abstract

Lepidoptera is the second most diverse insect order outnumbered only by the Coeleptera. Acetylcholinesterase (AChE) is the major target site for insecticides. Extensive use of insecticides, to inhibit the function of this enzyme, have resulted in the development of insecticide resistance. Complete knowledge of the target proteins is very important to know the cause of resistance. Computational annotation of insect acetylcholinesterase can be helpful for the characterization of this important protein. Acetylcholinesterase of fourteen lepidopteran insect pest species was annotated by using different bioinformatics tools. AChE in all the species was hydrophilic and thermostable. All the species showed lower values for instability index except L. orbonalis, S. exigua and T. absoluta . Highest percentage of Arg, Asp, Asn, Gln and Cys were recorded in P. rapae . High percentage of Cys and Gln might be reason for insecticide resistance development in P. rapae. Phylogenetic analysis revealed the AChE in T. absoluta , L. orbonalis and S. exigua are closely related and emerged from same primary branch. Three functional motifs were predicted in eleven species while only two were found in L. orbonalis, S. exigua and T. absoluta. AChE in eleven species followed secretory pathway and have signal peptides. No signal peptides were predicted for S. exigua , L. orbonalis and T. absoluta and follow non secretory pathway. Arginine methylation and cysteine palmotylation was found in all species except S. exigua , L. orbonalis and T. absoluta . Glycosylphosphatidylinositol (GPI) anchor was predicted in only nine species.

Larvicidal Activity against Spodoptera frugiperda of some Constituents from two Diospyros Species. In silico Pesticide‐likeness Properties, Acetylcholinesterase Activity and Molecular Docking

“…The compounds isolated from the two Diospyros species (3, 4, 5, 11, 12, 13, 14, 17, 18, 20), origanal (21), limonin (22), were tested for AChE inhibitory activity, using the insecticide phorate sulfoxide (23) as positive reference, since organophosphate insecticides act as AChE inhibitors by their binding to the catalytic site in this protein. [51] Published reports have indicated that AChE is a key target in the resistance mechanisms developed by Lepidoptera such as S. frugiperda, [52] therefore, we chose to use this protein as a model in this work. Most of the compounds displayed relatively low percentages of inhibition (Table 3), therefore, the media inhibitory concentration (IC 50 ) values were calculated only for those compounds with 50 % or greater inhibition ( 21) is related to the decrease of the activity as an inhibitor of AChE.…”

“…Interestingly, the AChE inhibitory activity for betulinic acid (11) has been reported in the context of research on therapeutic substances against Alzheimer's disease using the model of AChE from Torpedo californica. [52]…”

Potential of Essential Oil-Based Anticholinesterase Insecticides against Anopheles Vectors: A Review

“…For example, the insect heart rate and contraction are regulated by glutamate and other neurotransmitters including ACh, norepinephrine, dopamine, serotonin and octopamine [ 66 ]. ACh is a key excitatory neurotransmitter in the insect nervous system [ 67 ].…”

“…The catalytic serine (Ser 360 ; Figure 3 A) is the target for covalent insecticides, including organophosphates and carbamates [ 61 , 62 ]. These insecticides establish a covalent bond with AChE through phosphorylation and carbamoylation, respectively [ 67 ]. The inhibition of AChE leads to ACh accumulation that eventually results in over-stimulation of postsynaptic cholinergic receptors [ 76 ].…”

Synthesis and characterization of a novel stimuli-responsive zein nano delivery system for the controlled release of emamectin benzoate

“…Most Lepidopteran insect larvae are phytophagous 2 and destructive, 3 resulting in severe production losses in agricultural and forestry crops, fruit trees, tea, vegetables, and flowers. Meanwhile, some Lepidopteran pests have developed high resistance to insecticides, 4 increasing the difficulty of prevention and control. Moreover, repeated application of insecticide chemicals negatively affects pesticide efficacy, soil microorganisms, environment safety, people's health, and other beneficial insects.…”