EAPSI: Structure and mechanism of a mosquito larvicidal toxin secreted by entomopathogenic Xenorhabdus bacteria

Kim Ilhwan, Madison WI

Investigators

Abstract

Disease prevention depends heavily on mosquito control since there are no approved vaccines to mosquito-transmitted disease such as dengue and yellow fever. However, conventional mosquito control programs use chemical and synthetic pesticides which induce non-target effects against important insect species and result in development of resistance in mosquitoes. Alternative control method using bio-insecticide is needed. This project will characterize the structure and mechanism of a newly discovered mosquito larvicidal peptide produced by Xenorhabdus bacteria. The knowledge gained through this effort will lead to a development of environmentally safe and mosquito-specific bio-insecticide. The proposed research will be conducted in collaboration with Dr. Do-Young Kim, a noted expert on proteomics research, at Pohang Technopark- Pohang Center for Evaluation of Biomaterials in South Korea. The expertise and equipments provided by Dr. Kim in structural analysis and microscopy study will play a pivotal role in the proposed research. Structural analysis of toxin peptide will be conducted using a linear ion trap-Orbitrap (LTQ-Orbitrap) mass spectrometer. Amino acid composition of toxin peptide will be analyzed through an amino acid column connected to high pressure liquid chromatography equipped with fluorescence detector (HPLC-FLD). The super-resolution light microscope, N-SIM/N-STORM, will be used to examine how mosquito larvicidal toxin peptide alters mosquito midgut morphology and disrupts midgut epithelial cells. The successful outcome in this study will lead to the introduction of a new bio-pesticide. Although mosquito-borne diseases have been declared of being eradicated in the United States, it still affects millions of lives throughout the world. By developing a cost-effective and environmentally-friendly pesticide, this project aims to make a discovery that will improve global population health. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Korea.