Small peptides inhibit gut trypsin‐like proteases and impairAnticarsia gemmatalis(Lepidoptera:Noctuidae) survival and development

Abstract

BACKGROUND Anticarsia gemmatalis larvae are key defoliating pests of soybean plants. Inorganic insecticides, harmful to the environment and human health, are the main molecules used in the control of this pest. To apply more sustainable management methods, organic molecules with high specificities, such as proteinaceous protease inhibitors, have been sought. Thus, molecular docking studies, kinetics assays, and biological tests were performed to evaluate the inhibitory activity of two peptides (GORE1 and GORE2) rationally designed to inhibit trypsin‐like enzymes, which are the main proteases of A. gemmatalis midgut. RESULTS The molecular docking simulations revealed critical hydrogen bonding patterns of the peptides with key active site residues of trypsin‐like proteases of A. gemmatalis and other Lepidopteran insects. The negative values of binding energy indicate that hydrogen bonds potentiate the tight binding of the peptides with trypsin‐like proteases, predicting an effective inhibition. The inhibition's rate constants (Ki) were 0.49 and 0.10 mM for GORE1 and GORE2, resulting in effective inhibition of the activity trypsin on the L‐BApNA substrate in the in vitro tests, indicating that the peptide GORE2 has higher inhibitory capacity on the A. gemmatalis trypsins. In addition, the two peptides were determined to be reversible competitive inhibitors. The in vivo test demonstrated that the peptides harm the survival and development of A. gemmatalis larvae. CONCLUSION These results suggest that these peptides are potential candidates in the management of A. gemmatalis larvae and provide baseline information for the design of new trypsin‐like inhibitors based on peptidomimetic tools. © 2020 Society of Chemical Industry

Structural analysis and inhibition capacity of dioscorin protein yam: Theoretical study by molecular docking and dynamic simulations

“…On the other hand, in silico tools have recently become an unavoidable approach for the optimization of protein–protein complexes and the design of new molecules from the study of the interaction between these proteins related to pest management (de Almeida Barros, Meriño‐Cabrera, Severiche Castro, da Silva Junior, de Oliveira, et al, 2022; de Almeida Barros, Meriño‐Cabrera, Severiche Castro, da Silva Júnior, Schultz, et al, 2022; de Almeida Barros et al, 2021; Halim et al, 2022; Machado et al, 2020; Meriño‐Cabrera, de Oliveira Mendes, et al, 2020; Meriño‐Cabrera, Severiche Castro, et al, 2020; Meriño‐Cabrera, et al, 2022). Using tools such as molecular modeling of proteins, which allows us to determine the three‐dimensional (3D) structure of the sequences of receptors and ligands such as yam disocorins; protein–protein molecular docking, to determine the affinity site and energy of the inhibitor to the digestive enzymes of interest; and study of the interface using software such as Pymol and Discovery, which allow exploring inhibitory residues that bind to the active site of the enzyme and/or potential to reduce enzyme activity (hot‐spot residues), which would be expensive and slowly by experimental methods (Childers & Daggett, 2017); In addition, molecular dynamics (MD) simulations are performed to analyze the stability of the protein–protein complex and the free binding energy in aqueous solution estimation, allowing to understand several underlying biological phenomena, such as enzyme inhibition (Patel & Ytreberg, 2018).…”

Extensive reprogramming of protein isoforms and histopathological alterations in the midgut of Anticarsia gemmatalis fed with protease inhibitors

“…Many natural peptides and synthetic inhibitors of trypsin have an arginine or a lysine that binds in the specificity site of the enzyme, which is near the catalytic triad responsible for the catalysis (de Almeida Barros et al, 2021; Presnell et al, 1998). In particular, benzamidine, a structural mimic of arginine and itself a potent inhibitor (Mares‐Guia & Shaw, 1965), is the primary component of many larger inhibitors.…”