Intestinal proteases profiling from Anticarsia gemmatalis and their binding to inhibitors

Although the importance of intestinal hydrolases is recognized, there is little information on the intestinal proteome of lepidopterans such as Anticarsia gemmatalis. Thus, we carried out the proteomic analysis of the A. gemmatalis intestine to characterize the proteases by LC/MS. We examined the interactions of proteins identified with protease inhibitors (PI) using molecular docking. We found 54 expressed antigens for intestinal protease, suggesting multiple important isoforms. The hydrolytic arsenal featured allows for a more comprehensive understanding of insect feeding. The docking analysis showed that the soybean PI (SKTI) could bind efficiently with the trypsin sequences and, therefore, insect resistance does not seem to involve changing the sequences of the PI binding site. In addition, a SERPIN was identified and the interaction analysis showed the inhibitor binding site is in contact with the catalytic site of trypsin, possibly acting as a regulator. In addition, this SERPIN and the identified PI sequences can be targets for the control of proteolytic activity in the caterpillar intestine and serve as a support for the rational design of a molecule with greater stability, less prone to cleavage by proteases and viable for the control of insect pests such as A. gemmatalis.

Automated summary

This study characterized the intestinal proteome of the lepidopteran Anticarsia gemmatalis, identifying multiple important isoforms of intestinal proteases and analyzing their interactions with inhibitors. The docking analysis revealed efficient binding between soybean PI and trypsin sequences without changes in the binding site sequence. Additionally, a SERPIN was identified as a potential regulator, providing support for the rational design of molecules with greater stability and resistance to protease cleavage for controlling insect pests like A. gemmatalis.