Arginine-containing dipeptides decrease affinity of gut trypsins and compromise soybean pest development.

Area of Science:

• Biochemistry
• Entomology
• Agricultural Science

Background:

• Gut trypsin is crucial for insect pest development, particularly in Lepidoptera.
• Protein inhibitors offer a strategy for modulating insect gut function.
• Targeting insect proteases is a key area in pest management research.

Purpose of the Study:

• To characterize gut trypsin activity in Anticarsia gemmatalis larvae.
• To evaluate the inhibitory potential of arginine-containing dipeptides against A. gemmatalis trypsins.
• To assess the anti-insect performance of these dipeptides on larval development.

Main Methods:

• In silico molecular docking to assess peptide-trypsin affinity.
• In vitro enzyme kinetics to determine inhibitory effects.
• Larval bioassays measuring survival and weight changes.

Main Results:

• Arginine-containing dipeptides exhibited higher affinity for A. gemmatalis trypsin active sites compared to lysine-containing peptides.
• In vitro studies confirmed competitive inhibition and significant reduction in gut trypsin activity.
• Larval exposure led to reduced survival rates and decreased larval weight.

Conclusions:

• Arginine-containing dipeptides are effective inhibitors of A. gemmatalis gut trypsin.
• These peptides demonstrate significant anti-insect potential, impacting larval survival and development.
• Optimized small peptides represent a viable strategy for lepidopteran pest control in agriculture.