Functional characterization of Helicoverpa armigera trehalase and investigation of physiological effects caused due to its inhibition by Validamycin A formulation.
Trehalase catalyzes hydrolysis of trehalose and plays a crucial role in insect metabolism. In the present study, phylogenetic analysis and multiple sequence alignment suggested that H. armigera trehalase-1 (HaTre-1) is closely related to other soluble trehalases with conserved signature features and functional sites. We have expressed and purified recombinant HaTre-1 having Vmax ~0.16mM/min and KM ~1.34mM. Inhibition kinetics and Microscale thermophoresis illustrated competitive inhibition of HaTre-1 by Validamycin A having Ki ~3nM and KD ~542nM, respectively. Docking studies of HaTre-1 with Validamycin A indicated that it binds at the active site with multiple hydrogen bonds. Ingestion of Validamycin A resulted in impediment of H. armigera growth and developmental defects. Treated larvae showed concentration dependent decrease in fecundity. It also led to total inhibition of ex-vivo trehalase activity and down-regulation of gene expression of HaTre-1. Relatively high insect mortality was observed on tomato plants sprayed with combination of Validamycin A with Azadirachta indica (neem) and Pongamia pinnata (karanj) oil as compared to the individual treatments. This report has re-emphasized trehalase inhibition as a potential insecticidal strategy and also recommends Validamycin A as a prospective value-added ingredient to commercial bio-pesticide formulations.
['Adhav|Anmol S|AS|', 'Kokane|Surabhi R|SR|', 'Joshi|Rakesh S|RS|']
D000595:Amino Acid Sequence D000818:Animals D001681:Biological Assay D004339:Drug Compounding D004357:Drug Synergism D004791:Enzyme Inhibitors D005247:Feeding Behavior D006863:Hydrogen-Ion Concentration D007294:Inositol D007700:Kinetics D007915:Lepidoptera D010802:Phylogeny D010938:Plant Oils D052596:Pongamia D000072417:Protein Domains D012333:RNA, Messenger D013696:Temperature D014198:Trehalase
Helicoverpa armigera Trehalase Validamycin A Trehalase inhibition