Increase of permeability in lipid vesicles caused by antimicrobial peptide Protegrin-1

CHED 1412

Ting Ann Siaw, tsiaw@uchicago.edu, Department of Chemistry, The Institute for Biophysical Dynamics, The James Franck Institute,The University of Chicago, 929 E. 57th St., CIS-ESB31, Chicago, IL 60637, Kin Lok H. Lam, kllam@uchicago.edu, Department of Physics, The Institute for Biophysical Dynamics, The James Franck Institute, The University of Chicago, 929 E. 57th St., CIS-ESB31, Chicago, IL 60637, Yuji Ishitsuka, Department of Chemistry, The Institute for Biophysical Dynamics, The James Franck Institute, The University of Chicago, 929 E. 57th St., CIS-ESB31, chicago, IL 60637, Alan J. Waring, awaring@ucla.edu, Department of Pediatrics, Harbor/UCLA, Torrance, CA 90502, Robert I. Lehrer, Department of Medicine, UCLA, Los Angeles, and Ka Yee C. Lee, kayeelee@uchicago.edu, Department of Chemistry, The Institute for Biophysical Dynamics and The James Franck Institute, The University of Chicago, 929 E. 57th St., GCIS-E139B, Chicago, IL 60637.
Protegrin-1 (PG-1), a cationic antimicrobial peptide, kills bacteria by causing an increase in membrane permeability to ions or larger molecules. It has been proposed that there is a peptide to lipid ratio threshold above which there is leakage of endogenous material. To study the effects of PG-1 on membrane permeability, we carried out a series of dye leakage experiments where bacterial cell membranes are modeled by phospholipid vesicles. Our experiments demonstrate that PG-1 induces leakage from these vesicles. These results show that the degree of leakage activity is dependent on the concentration of PG-1 and the presence of anionic lipid in the vesicles.
 

Undergraduate Research Poster Session: Physical Chemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Chemical Education

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007