arXiv subjects

Guillaume Brotons

Publications and source records attributed to Guillaume Brotons.

2 recordsLinked to original sources

arXiv2015

Interaction of Alamethicin Pores in DMPC Bilayers

We have investigated the x-ray scattering signal of highly aligned multilayers of the zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine containing pores formed by the antimicrobial peptide alamethicin as a function of the peptide/lipid ratio. We are able to obtain information on the structure factor of the pore fluid, which then yields the interaction potential between pores in the plane of the bilayers. Aside from a hard core with a radius corresponding to the geometric radius of the pore, we find a repulsive lipid-mediated interaction with a range of $\simeq 30$ Å and a contact value of 2.4 $k_BT$. This result is in qualitative agreement with recent theoretical models.

cond-mat.soft↗

arXiv2015

Dynamics of bulk fluctuations in a lamellar phase studied by coherent x-ray scattering

Using x-ray photon correlation spectroscopy, we studied the layer fluctuations in the lamellar phase of an ionic lyotropic system. We measured the relaxation rate of in-plane (undulation) fluctuations as a function of the wave vector. Static and dynamic results obtained during the same experiment were combined to yield the values of both elastic constants of the lamellar phase (compression and bending moduli) as well as that of the sliding viscosity. The results are in very good agreement with dynamic light-scattering data, validating the use of the technique in ordered phases.

cond-mat.soft↗