Phase transformations during heating of β-crystallized isotactic polypropylenes were investigated by simultaneous SAXS, WAXD, and DSC measurements. The isotactic polypropylene samples containing the larger amount of β-form crystals were prepared by a temperature-gradient method or with the used of a nucleating agent. DSC deconvolution analysis successfully reproduced the duplicated endotherms and exotherms for both samples, considering WAXD and SAXS changes with heating. The obtained results indicated characteristic phase transformations during heating, including the temporary melting of the initial β-form and synchronized recrystallization into the R-form before the final melting of R-form crystals.

Based on high statistical quality wide-angle X-ray scattering data for the unfolding-refolding process of hen egg-white lysozyme (HEWL), we have analysed the change of the hydration shell as a function temperature using the program CRYSOL. The present results suggest that the decrease of the hydration-shell density starts from a lower temperature than the transition temperature of the collapse of the tertiary structure of HEWL. Although the use of CRYSOL for scattering data for proteins before the transition has an apparent limitation, the collapse of the hydration shell prior to the unfolding of HEWL agrees with a slight tendency of the radius of gyration to decrease during the thermal unfolding process.

No abstract

Using small-angle and wide-angle X-ray scattering techniques it has been possible to clarify the helix-to-sheet (cross-) transition and the stacking process of the cross-sheet of apomyoglobin as a model for amyloid. The present results indicate that the cross-formation and the pleated sheet stacking start concurrently and that the stacking continues progressively after the saturation of the cross-formation. The effect of glycosphingolipids on the above processes has also been studied. At high molar ratio of glycosphingolipid to apomyoglobin the growth of the amyloid is suppressed.

We have characterized the structures of ganglioside (G D3 ) micelle and G D3 / cholesterol mixtures, and have determined the permeability of water across a membrane of G D3 /cholesterol/phospholipid uni-lamellar vesicle. We have found that monovalent Na + and K + cations affect the permeability of water differently. We have found also that the permeability of water is greatly enhanced by the K + ion, suggesting the function of the G D3 /cholesterol rich clusters on neuronal excitations by K + . The complimentary use of small-angle X-ray and neutron scattering techniques is useful to determine the permeability of water across a vesicle membrane.