RT Journal Article
T1 SP-A permeabilizes lipopolysaccharide membranes by forming protein aggregates that extract lipids from the membrane
A1 Cañadas Benito, Olga
A1 García Verdugo, Ignacio
A1 Keough, Kevin
A1 Casals Carro, María Cristina
A2 Axelsen, Paul
AB Surfactant protein A (SP-A) is known to cause bacterial permeabilization. The aim of this work was to gain insight into the mechanism by which SP-A induces permeabilization of rough lipopolysaccharide (Re-LPS) membranes. In the presence of calcium, large interconnected aggregates of fluorescently labeled TR-SP-A were observed on the surface of Re-LPS films by epifluorescence microscopy. Using Re-LPS monolayer relaxation experiments at constant surface pressure, we demonstrated that SP-A induced Re-LPS molecular loss by promoting the formation of three-dimensional lipid-protein aggregates in Re-LPS membranes. This resulted in decreased van der Waals interactions between Re-LPS acyl chains, as determined by differential scanning calorimetry, which rendered the membrane leaky. We also showed that the coexistence of gel and fluid lipid phases within the Re-LPS membrane conferred susceptibility to SP-A-mediated permeabilization. Taken together, our results seem to indicate that the calcium-dependent permeabilization of Re-LPS membranes by SP-A is related to the extraction of LPS molecules from the membrane due to the formation of calcium-mediated protein aggregates that contain LPS.
PB Biophysical Society
SN 0006-3495
YR 2008
FD 2008
LK https://hdl.handle.net/20.500.14352/93210
UL https://hdl.handle.net/20.500.14352/93210
LA eng
NO Cañadas O, García-Verdugo I, Keough KM, Casals C. 2008. SP-A permeabilizes lipopolysaccharide membranes by forming protein aggregates that extract lipids from the membrane. Biophys. J. 2008 Oct; 95(7): 3287-94
NO Ministerio de Educación y Ciencia (España)
NO Instituto de Salud Carlos III
NO Comunidad de Madrid
NO Fundación Médica MM
NO Canadian Institutes of Health Research
DS Docta Complutense
RD 20 abr 2025