MAXIMIN 3 BINDING AND LEAKAGE OF MEMBRANES MADE WITH ESCHERICHIA COLI POLAR LIPID EXTRACT

Abstract

Due to the overwhelming amount of antibiotic resistance developing in bacteria, a new method for rupturing bacterial membranes has been suggested. Antimicrobial peptides (AMPs) are short peptides that produce a leak in a bacterial cell by binding to the bacteria’s phospholipid bilayer membrane and creating a hole in the membrane. Currently, most AMPs are too cytotoxic for the human body and are not ready to be used as a treatment for bacterial infections. The main goal for this research is to further study AMPs’ behavior with Escherichia coli vesicles, as well as their degree of leakage. This project focused on membranes made with Escherichia coli polar lipid extract and used the AMP Maximin 3 to induce leakage. A leakage assay was used to calculate the percent vesicle leakage at different peptide concentrations. The leakage assay technique uses a vesicle prepared by the addition of E. coli lipids in a mixture of buffer and dye or dye-quencher. The lipid was passed through a microscale extrusion membrane to create dye-filled vesicles. After the extrusion was completed, the vesicles were dialyzed overnight. After dialysis, three fluorimeter measurements were taken: first of the vesicles alone; then of the vesicle with a peptide; and lastly of the vesicle, peptide, and detergent. Through measurement and quantification of the degree of leakage induced by Maximin 3 in E. coli membrane, an enhanced understanding of the membrane disrupting the mechanism of AMPs can be produced.