Novel proteinase inhibitor from the hemolymph of soybean pest Anticarsia gemmatalis (lepidóptera: Noctuidae): Structural modeling and enzymatic kinetic

Abstract

New approaches are needed to reduce risks to the environment and natural enemies and to avoid or delay the onset of insecticide resistance. The use of insecticides based on proteinase inhibitors of hemolymph is an alternative for the control of Lepidoptera pests primarily by having low toxicity and short persistence in the environment. Thus, in this study, we describe the purification process and identification of protease inhibitors from hemolymph Anticarsia gemmatalis and their activities against trypsin enzymes. Furthermore, the three-dimensional (3D) structure of the inhibitor and binding mode to trypsin enzymes was determined, and the stability of the inhibitory activity in several pHs and temperature values was evaluated. The inhibitor was characterized as a serpin family inhibitor and named A. gemmatalis hemolymph serpin inhibitor (AHSI), with an approximate mass of 38 ± 2 kDa, highly stable to temperature and pH variations, and with inhibitory capacity on bovine trypsin and gut trypsin of A. gemmatalis demonstrated by calculated K i values and affinity energy through molecular docking, being a reversible competitive inhibitor that binds to the active site of

An Efficient and Simple Method for Collecting Haemolymph of Cerambycidae (Insecta: Coleoptera) Adults

“…When using the double centrifugation method to collect haemolymph, most studies apply centrifugation after making open wounds on the dorsal blood vessels or abdomen of insects. However, the back and abdomen are close to the stomach, malleus and other organs that store food and excrement in the midgut and hindgut, and high-speed centrifugation in the presence of wounds in the surrounding body wall will cause repeated collisions with the hard wall of the centrifuge tube, leading to internal and external damage and increased contaminants [ 34 , 35 , 36 ]. Proposals to reduce contamination include reducing the centrifugation speed, prolonging the centrifugation time and adding chemical reagents to the bottom of the tube to prevent melanisation [ 37 ].…”