Patterned domains of supported phospholipid bilayer using microcontact printing of Pll-g-PEG molecules.

In this work, we propose a reliable microcontact printing (μCP) process for generating Patterned Supported Phospholipids Bilayer (P-SPB) confined by Poly-L-(lysine)-grafted-polyethylene(glycol) (Pll-g-PEG) molecular barriers. The efficiency of Pll-g-PEG for inhibiting the fusion process of incubated liposome was first analyzed by Quartz Micro Balance (QCM) measurements. The quality and stability of Pll-g-PEG patterns were then both verified by fluorescence microscopy and Atomic Force Microscopy (AFM) in liquid media.

Deciphering the structure, growth and assembly of amyloid-like fibrils using high-speed atomic force microscopy.

Formation of fibrillar structures of proteins that deposit into aggregates has been suggested to play a key role in various neurodegenerative diseases. However mechanisms and dynamics of fibrillization remains to be elucidated. We have previously established that lithostathine, a protein overexpressed in the pre-clinical stages of Alzheimer's disease and present in the pathognomonic lesions associated with this disease, form fibrillar aggregates after its N-terminal truncation.

Nanoscale topography of hepatitis B antigen particles by atomic force microscopy.

Hepatitis B virus envelope is mainly composed of three forms of the same protein expressed from different start codons of the same open reading frame. The smaller form named S protein corresponds to the C-terminal common region and represents about 80% of the envelope proteins. It is mainly referred as hepatitis B virus surface antigen (HBsAg).

Organization of influenza A virus envelope at neutral and low pH.

Fusion of the influenza A H1N1 virus envelope with the endosomal membrane at low pH allows the intracellular delivery of the viral genome and plays an essential role in the infection process. Low pH induces an irreversible modification of the virus envelope, which has so far resisted 3D structural analysis, partly due to the virus pleiomorphy. This study showed that atomic force microscopy (AFM) in physiological buffer could be used to image the structural details of the virus envelope, both at neutral pH and after a low-pH treatment.

Surface topography of membrane domains.

Elucidating origin, composition, size, and lifetime of microdomains in biological membranes remains a major issue for the understanding of cell biology. For lipid domains, the lack of a direct access to the behaviour of samples at the mesoscopic scale has constituted for long a major obstacle to their characterization, even in simple model systems made of immiscible binary mixtures. By its capacity to image soft surfaces with a resolution that extends from the molecular to the microscopic level, in air as well as under liquid, atomic force microscopy (AFM) has filled this gap and has become an inescapable tool in the study of the surface topography of model membrane domains, the first essential step for the understanding of biomembranes organization.