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Alpha-Helical Peptide-Induced Vesicle Rupture Revealing New Insight into the Vesicle Fusion Process As Monitored in Situ by Quartz Crystal Microbalance-Dissipation and Reflectometry

N. J. Cho ; Guoliang Wang (Institutionen för teknisk fysik, Biologisk fysik) ; Malin Edvardsson (Institutionen för teknisk fysik, Biologisk fysik) ; J. S. Glenn ; Fredrik Höök (Institutionen för teknisk fysik, Biologisk fysik) ; C. W. Frank
Analytical Chemistry (0003-2700). Vol. 81 (2009), 12, p. 4752-4761.
[Artikel, refereegranskad vetenskaplig]

We have used simultaneous quartz crystal microbalance-dissipation (QCM-D) monitoring and four-detector optical reflectometry to monitor in situ the structural transformation of intact vesicles to a lipid bilayer on a gold surface. The structural transformation of lipid vesicles to a bilayer was achieved by introducing a particular amphiphathic, a-helical (AH) peptide. The combined experimental apparatus allows us to simultaneously follow the acoustic and optical property, changes of the vesicle rupturing process upon interaction with AH peptides. While QCM-D and reflectometry have similar sensitivities in terms of mass and thickness resolution, there are unique advantages in operating these techniques simultaneously on the same substrate. These advantages permit us to (1) follow the complex interaction between AH peptides and intact vesicles with both acoustic and optical mass measurements, (2) calculate the amount of dynamically coupled water during the interaction between AH peptides and intact vesicles, (3) demonstrate that the unexpectedly large increase of both adsorbed mass and the film's energy dissipation is mainly caused by swelling of the vesicles during the binding interaction with AH peptides, and (4) permit us to understand the structural transformation from intact vesicles to a bilayer via the AH peptide interaction by monitoring viscoelastic properties, acoustic mass, optical mass, and thickness changes of both the binding and destabilization processes. From the deduced "hydration signature" we followed the complex transformation of lipid assemblies. On the basis of this information, a mechanism of this structural transformation is proposed that provides new insight into the process of vesicle fusion on solid substrates.

Nyckelord: surface-plasmon resonance, atomic-force microscopy, lipid-bilayer, solid-surfaces, coupled water, qcm-d, adsorption, ellipsometry, immobilization, biosensor



Denna post skapades 2010-02-24.
CPL Pubid: 114669

 

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Institutioner (Chalmers)

Institutionen för teknisk fysik, Biologisk fysik (2007-2015)

Ämnesområden

Biofysik

Chalmers infrastruktur