Molecular dynamics characterization of n-octyl-beta-D-glucopyranoside micelle structure in aqueous solution

n-Octyl-beta-D-glueopyranoside (OG) is a non-ionic glycolipid, which is used widely in biotechnical and biochemical applications. All-atom molecular dynamics simulations from two different initial coordinates and velocities in explicit solvent have been performed to characterize the structural behaviour of an OG aggregate at equilibrium conditions. Geometric packing properties determined from the simulations and small angle neutron scattering experiment state that OG micelles are more likely to exist in a non-spherical shape, even at the concentration range near to the critical micelle concentration (0.025 M). Despite few large deviations in the principal moment of inertia ratios, the average micelle shape calculated from both simulations is a prolate ellipsoid. The deviations at these time scales are presumably the temporary shape change of a micelle. However, the size of the micelle and the accessible surface areas were constant during the simulations with the micelle surface being rough and partially elongated. Radial distribution functions computed for the hydroxyl oxygen atoms of an OG show sharper peaks at a minimum van der Waals contact distance than the acetal oxygen, ring oxygen, and anomeric carbon atoms. This result indicates that these atoms are pointed outwards at the hydrophilic/hydrophobic interface, form hydrogen bonds with the water molecules, and thus hydrate the micelle surface effectively. (c) 2005 Elsevier Inc. All rights reserved

Glycolipids from a colloid chemical point of view

Glycolipids are a group of compounds with a broad range of applications. Two types of glycolipids (alkylpolyglycosides and gangliosides) were examined with regard to their physicochemical properties. Despite their structural differences, they have in common that they are amphiphilic molecules and able to aggregate to form monolayers, bilayers, micelles, lyothropic mesophases or vesicles. The structures of glycolipid micelles were investigated by different experimental techniques in addition to molecular dynamic simulations. The knowledge of the physicochemical properties of gangliosides enables a better understanding of their biological functions. Structural features were obtained for the monosialogangliosides GM1, GM2 and GT1b from bovine brain by means of mass spectrometry. Further the aggregation behaviour was determined by small-angle neutron and dynamic light scattering experiments. Interaction studies of these compounds were carried out by means of surface plasmon resonance using gangliosides incorporated liposomes. They were used as model membranes that interact with the lectins WGA, RCA and HPA. The interaction of lectins immobilized to a modified silicon surface was investigated by in-situ ellipsometry

Location privacy-preserving mobile crowd sensing with anonymous reputation

In this paper, we give a location privacy-preserving solution for the mobile crowd sensing (MCS) system. The solution makes use of the blind signature technique for anonymous authentication and allows a mobile user to participate in the MCS for certain times set in the registration. Furthermore, we introduce a concept of anonymous reputation for mobile users on the basis of the blind signature technique as well. An anonymous reputation can be referred by the MCS platform when assigning tasks to a mobile user and can be upgraded or downgraded by the MCS platform, depending on the quality of reports submitted by the mobile user. For the security analysis, we provide security proofs for our solution on the basis of our formal definitions for anonymity, unlinkability and unforgeability for MCS. The performance analysis and experiments have shown that our solution is more efficient than existing solutions for MCS based on the blind signature technique.NRF (Natl Research Foundation, S’pore)Accepted versio

Location Privacy-Preserving Mobile Crowd Sensing with Anonymous Reputation

In this paper, we give a location privacy-preserving solution for the mobile crowd sensing (MCS) system. The solution makes use of the blind signature technique for anonymous authentication and allows a mobile user to participate in the MCS for certain times set in the registration. Furthermore, we introduce a concept of anonymous reputation for mobile users on the basis of the blind signature technique as well. An anonymous reputation can be referred by the MCS platform when assigning tasks to a mobile user and can be upgraded or downgraded by the MCS platform, depending on the quality of reports submitted by the mobile user. For the security analysis, we provide security proofs for our solution on the basis of our formal definitions for anonymity, unlinkability and unforgeability for MCS. The performance analysis and experiments have shown that our solution is more efficient than existing solutions for MCS based on the blind signature technique