Interaction of a peptide nanotube with a water–membrane interface

We have prepared two-dimensional (2D) crystals of tetanus toxin using procedures developed by Uzgiris and Kornberg for the directed production of 2D crystals of monoclonal antibodies at an antigen-phospholipid monolayer interface. The tetanus toxin crystals were formed using a small mole fraction of the natural receptor, GT1, incorporated into phosphatidyl choline monolayers. The crystals formed at low concentration overnight. Two dimensional crystals of this type are particularly useful for structure determination using electron microscopy and computer image refinement. Three dimensional (3D) structural information can be derived from these crystals by computer reconstruction of photographs of toxin crystals taken at different tilt angles. Such 3D reconstructions may help elucidate the mechanism of entry of the enzymatic subunit of toxins into cells, particularly since these crystals form directly on a membrane interface at similar concentrations of ganglioside GT1 to the natural cellular receptors.

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Phase Transitions in Phospholipid Monolayers Studied by Atomic Force Microscopy and Langmuir-Blodgett Technique

Revista de Chimie ◽

10.37358/rc.08.11.2008 ◽

2008 ◽

Vol 59 (11) ◽

Author(s):

Maria Tomoaia-Cotisel ◽

Aurora Mocanu

Keyword(s):

Atomic Force Microscopy ◽

Lipid Membrane ◽

Phase Behaviour ◽

Membrane Interface ◽

Force Microscopy ◽

Langmuir Blodgett ◽

Atomic Force ◽

Phospholipid Monolayers ◽

Air Water Interface ◽

Condensed Liquid

The phase behaviour and surface structure of dipalmitoyl phosphatidyl choline (DPPC) monolayers at the air/water interface, in the absence and the presence of procaine, have been investigated by Langmuir-Blodgett (LB) technique and atomic force microscopy. The LB films were transferred on mica, at a controlled surface pressure, characteristic for the expanded liquid to condensed liquid phase transition of pure DPPC monolayers. The results indicate that procaine penetrates into and specifically interacts with phospholipid monolayers stabilizing the lipid membrane interface.

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Structure-Based Modelling and Dynamics of MurM, a Streptococcus Pneumoniae Penicillin Resistance Determinant that Functions at the Cytoplasmic Membrane Interface

SSRN Electronic Journal ◽

10.2139/ssrn.3641935 ◽

2020 ◽

Author(s):

Anna York ◽

Adrian John Lloyd ◽

Charo I. del Genio ◽

Jonathan Shearer ◽

Karen J. Hinxman ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Cytoplasmic Membrane ◽

Resistance Determinant ◽

Penicillin Resistance ◽

Membrane Interface

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Structural dynamics of peptide nanotube and their conformational implication investigation by molecular modeling, molecular mechanics and molecular dynamics

Materials Today Proceedings ◽

10.1016/j.matpr.2020.11.942 ◽

2021 ◽

Author(s):

Rajat Yadav ◽

Aman Sharma

Keyword(s):

Molecular Dynamics ◽

Molecular Modeling ◽

Molecular Mechanics ◽

Structural Dynamics ◽

Peptide Nanotube

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Transient Water Transport in Nafion Membranes Under Activity Gradients

ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 1 ◽

10.1115/fuelcell2010-33317 ◽

2010 ◽

Author(s):

T. Romero ◽

W. Me´rida

Keyword(s):

Water Content ◽

Water Transport ◽

Water Activity ◽

Thickness Variation ◽

Membrane Thickness ◽

Membrane Interface ◽

Rational Representation ◽

Transport Measurements ◽

Nafion Membranes ◽

The Time Domain

Transient water transport experiments on Nafion of different thicknesses were carried out in the temperature range of 30 to 70 °C. These experiments report on water transport measurements under activity gradients in the time domain for liquid and vapour equilibrated Nafion membranes. Using a permeability test rig with a gated valve, the water crossover was measured as a function of time. The typical response is shown as a time dependent flux, and it shows the dynamic transport from an initially dry condition up to the final steady state. Contrarily to previous reports from dynamic water transport measurements, where the activity gradient across the membrane is absent; in this work, the membrane was subjected to an activity gradient acting as the driving force to transport water from an environment with higher water activity to an environment with lower water activity through the membrane’s structure. Measurements explored temperature and membrane thickness variation effect on the transient response. Results showed dependency on temperature and a slower water transport rate across the vapour-membrane interface than for the liquid-membrane interface. These measurements showed the transport dependency on water content at the beginning of the experiment when the membrane was in a close-to-dry condition suggesting a transport phenomenon transition due to a reached critical water content value. The new protocol for transient measurements proposed here will allow the characterization of water transport dependency on membrane water content with a more rational representation of the membrane-environment interface.

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