Interactions of mast cell degranulating peptides with model membranes: a comparative biophysical study.
In the last decade, there has been renewed interest in biologically active peptides in fields like allergy, autoimmune diseases and antibiotic therapy. Mast cell degranulating peptides mimic G-protein receptors, showing different activity levels even among homologous peptides. Another important feature is their ability to interact directly with membrane phospholipids, in a fast and concentration-dependent way. The mechanism of action of peptide HR1 on model membranes was investigated comparatively to other mast cell degranulating peptides (Mastoparan, Eumenitin and Anoplin) to evidence the features that modulate their selectivity. Using vesicle leakage, single-channel recordings and zeta-potential measurements, we demonstrated that HR1 preferentially binds to anionic bilayers, accumulates, folds, and at very low concentrations, is able to insert and create membrane spanning ion-selective pores. We discuss the ion selectivity character of the pores based on the neutralization or screening of the peptides charges by the bilayer head group charges or dipoles.
Dos Santos Cabrera
Marcia Perez
MP
USP - University of São Paulo, Department of Physiology and Biophysics, Biomedical Sciences Institute, São Paulo, SP, Brazil. cabrera.marcia@gmail.com
Arcisio-Miranda
Manoel
M
da Costa
Laiana Cristina
LC
de Souza
Bibiana Monson
BM
Broggio Costa
Sabrina Thaís
ST
Palma
Mario Sérgio
MS
Ruggiero Neto
João
J
Procopio
Joaquim
J