Faculty Collaboration Database

The anti-angiogenic peptide anginex disrupts the cell membrane. J Mol Biol 2006 Mar 03;356(4):876-85

Date

01/13/2006

Pubmed ID

16403516

Pubmed Central ID

PMC2922962

DOI

10.1016/j.jmb.2005.12.006

Scopus ID

2-s2.0-31344438707 (requires institutional sign-in at Scopus site)   17 Citations

Abstract

Anginex is a synthetic beta-sheet peptide with anti-angiogenic and anti-tumor activity. When added to cultured endothelial cells at concentrations ranging from 2.5 microM to 25 microM, anginex induced cell death, which was reflected by a strong increase of subdiploid cells and fragments, loss of cellular ATP, and LDH release. Cytotoxicity remained the same whether cells were treated with anginex at 4 degrees C or at 37 degrees C. At low temperatures, fluorescein-conjugated anginex accumulated on the endothelial surface, but did not reach into the cytoplasm, indicating that the cell membrane is the primary target for the peptide. Within minutes of treatment, anginex caused endothelial cells to take up propidium iodide and undergo depolarization, both parameters characteristic for permeabilization of the cell membrane. This process was amplified when cells were activated with hydrogen peroxide. Red blood cell membranes were essentially unaffected by anginex. Anginex bound lipid bilayers with high affinity and with a clear preference for anionic over zwitterionic phospholipids. Structural studies by circular dichroism and solid-state nuclear magnetic resonance showed that anginex forms a beta-sheet and adopts a unique and highly ordered conformation upon binding to lipid membranes. This is consistent with lipid micellization or the formation of pore-forming beta-barrels. The data suggest that the cytotoxicity of anginex stems from its ability to target and disrupt the endothelial cell membrane, providing a possible explanation for the angiostatic activity of the peptide.

Author List

Pilch J, Franzin CM, Knowles LM, Ferrer FJ, Marassi FM, Ruoslahti E

Author

Francesca M. Marassi PhD Chair, Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cell Death
Cell Membrane
Cell Membrane Permeability
Cells, Cultured
Endothelial Cells
Endothelium, Vascular
Humans
Lipid Bilayers
Liposomes
Peptides
Protein Conformation
Proteins