Effects of disulfide bridges and backbone connectivity on water sorption by protein matrices.

Understanding the water sorption behavior of protein powders is important in applications such as the preservation of protein-based pharmaceuticals. Most globular proteins exhibit a characteristic sigmoidal water adsorption isotherm at ambient conditions. However, it is not well understood how water sorption behavior is influenced by intrinsic factors that are related to structural properties of proteins.

Molecular modeling and structural characterization of a high glycine-tyrosine hair keratin associated protein.

High glycine-tyrosine (HGT) proteins are an important constituent of the keratin associated proteins (KAPs) present in human hair. The glassy state physics of hair fibres are thought to be largely regulated by KAPs, which exist in an amorphous state and are readily affected by environmental conditions. However, there are no studies characterizing the individual KAPs.

Trehalose in hair care: heat styling benefits at high humidity.

Human hair switches that have been treated with trehalose solution and straightened using hot irons show longevity of the straight style even in high-humidity conditions. This anti-humidity benefit is especially noticeable if the straight style has been created at low relative humidity. It is proposed that hot-iron straightening of trehalose-treated switches produces in situ glassy forms of the sugar that act as water sinks at high humidity to provide anti-humidity benefits.

Prediction of vapour pressure using descriptors derived from molecular dynamics.

Vapour pressures of organic materials can be predicted to high levels of accuracy using cohesive energies and solubility parameters derived from molecular dynamics simulations that use good forcefields. It is found that over 90% of the correlation with vapour pressure is accounted for by a single cross term involving the product of either the molecular weight or molar volume of a molecule and its cohesive energy density.

Structures of carbohydrate-boronic acid complexes determined by NMR and molecular modelling in aqueous alkaline media.

The structures of thermodynamically stable aromatic boronic acid : cyclic carbohydrate chelates in aqueous alkaline media have been studied using 1H NMR spectroscopy and molecular modelling. It is found that interacting saccharides must necessarily possess a synperiplanar diol functionality for complexation to occur. While this is possible for furanose structures which tend to have a puckered planar geometry, for pyranose forms it is postulated that bis-complexation occurs with twist conformers of the pyranose ring, providing the ring has the requisite 1,2 : 3,4 polyol stereochemistry; specifically axial,equatorial : equatorial,axial or equatorial,axial : axial,equatorial orientations.

Linking atomistic and mesoscale simulations of water-soluble polymers.

A link between molecular and mesoscopic simulations for water-soluble polymers is made using the potential of mean force (PMF) method. Mesoscale parameters are adjusted to match selected thermodynamic quantities such as the monomer second virial coefficient or the limiting slope of the monomer adsorption isotherm, which are computed directly from atomistic PMFs. The method is illustrated by computing the bulk and surface interaction parameters (chi parameters in self-consistent field theory) for the adsorption of ethylene oxide (EO) and propylene oxide (PO) polymers from aqueous solution onto silica.