Polymer Bulletin, Vol.61, No.1, 107-117, 2008
Entrapment of immature amyloid protofilaments in the hydrophobic domain of schizophyllan
beta-1,3-glucan schizophyllan (SPG) is known to adopt a triple helical structure in nature and a random coil conformation in alkaline solutions which forms a hydrophobic domain when its random coil is renatured. This paper presents the complexation of amyloid with SPG, presumably owing to hydrophobic interactions between the beta-sheets and the SPG hydrophobic domain. Circular dichroism (CD) showed that complex had a negative band at 225 nm, indicating the presence of the stacked beta-sheets. However, wide angle X-ray scattering (WAXS) showed no clear inter beta-sheet diffractions that are generally observed at 1.0 nm in matured amyloid. Combining WAXS and CD, it can be concluded that lysozyme in complex has beta-sheets but the beta-sheets are not well stacked to give diffraction. Small angle X-ray scattering (SAXS) profile from complex can be reproduced using a combination of the cross-sectional Gunier and Debye-Bueche functions.