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Structuring and interactions of human β‐defensins 2 and 3 with model membranes
Author(s) -
Morgera Francesca,
Antcheva Nikolinka,
Pacor Sabrina,
Quaroni Luca,
Berti Federico,
Vaccari Lisa,
Tossi Alessandro
Publication year - 2008
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.981
Subject(s) - membrane , lipid bilayer , biophysics , chemistry , lysis , cytoplasm , biological membrane , microbiology and biotechnology , membrane biophysics , biochemistry , biology
β‐Defensins play an important role in both innate and adaptive immunity, displaying a direct anti‐microbial activity against a wide variety of micro‐organisms as well as interesting immuno‐modulatory effects on host cells. Interaction with biological membranes appears to be a central theme in modulating these activities, leading to different consequences such as membrane lysis, translocation into the cytoplasm or transfer to a receptor. We have investigated the structuring of human β‐defensins (hBD2 and hBD3) and rationally designed variants, in relation to their interactions with real and model membranes. Biophysical methods, such as circular dichroism (CD), transmission or reflection IR and dye release were used to probe their structure/activity in the presence of model membranes, while fluorimetric and flow cytometric assays were used to investigate the effects on prokaryotic cells. Our results indicate that structural features, such as the helical N ‐terminal domains and oligomerisation at the membrane surface, may modulate the efficiency of membrane insertion and selectivity for microbial or host‐cell membranes. We propose that both peptides interact with membranes as extended β‐sheet platforms that present amphipathic helices for insertion into the lipid bilayer. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.