Description: Mechanical Properties of Bare and Protein-Coated Giant Unilamellar Phospolipid Vesicles. A Comparative Study of Micropipet Aspiration and Atomic Force Microscopy

This title appears in the Scientific Report : 2010

Mechanical Properties of Bare and Protein-Coated Giant Unilamellar Phospolipid Vesicles. A Comparative Study of Micropipet Aspiration and Atomic Force Microscopy

In this study, protein-coated giant phospholipid vesicles were used to model cell plasma membranes coated by surface protein layers that increase membrane stiffness under mechanical or osmotic stress. These changed mechanical properties like bending stiffness, membrane area compressibility modulus,...

Personal Name(s):	Dieluweit, S.
	Csiszar, A. / Rubner, W. / Fleischhauer, J. / Houben, S. / Merkel, R.
Contributing Institute:	Biomechanik; IBN-4
Published in:	Langmuir, 26 (2010) S. 11041 - 11049
Imprint:	Washington, DC ACS Publ. 2010
Physical Description:	11041 - 11049
PubMed ID:	20355933
DOI:	10.1021/la1005242
Document Type:	Journal Article
Research Program:	BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung
Series Title:	Langmuir 26
Subject (ZB):	Mechanics Microscopy, Atomic Force Models, Theoretical Phospholipids: chemistry Unilamellar Liposomes: chemistry Phospholipids Unilamellar Liposomes J
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1021/la1005242 in citations.

In this study, protein-coated giant phospholipid vesicles were used to model cell plasma membranes coated by surface protein layers that increase membrane stiffness under mechanical or osmotic stress. These changed mechanical properties like bending stiffness, membrane area compressibility modulus, and effective Young's modulus were determined by micropipet aspiration, while bending stiffness, effective Young's modulus, and effective spring constant of vesicles were analyzed by AFM. The experimental setups, the applied models, and the results using both methods were compared here. As demonstrated before, we found that bare vesicles were best probed by micropipet aspiration due to its high sensitivity. The mechanical properties of vesicles with protein surface layers were, however, better determined by AFM because it enables very local deformations of the membrane with barely any structural damage to the protein layer. Mechanical properties of different species of coating proteins, here streptavidin and avidin, could be clearly distinguished using this technique.