Neutron small-angle scattering of E. coli ribosomes. A contrast variation study

Summary form only given, substantially as follows. The authors with the aid of neutron small-angle scattering with the contrast-variation method have established that for 50S and 70S ribosomal particles the RNA-protein distribution is such that the RNA component is located predominantly towards the interior and the protein towards the exterior of the particle. In contrast, the 30S subunit is much more homogeneous in its RNA-protein distribution. The shape of the 50S subunit has been determined at low resolution. The authors have extended these studies to 30S and 70S particles and found that the scattering density of the 70S ribosomes as for the 50S subunit decreases from the centre to the outer surface of the particle. Thus for 70S and 50S particles the r-RNA is located mainly in the interior and the bulk of the protein is distributed concentrically on the outer surface.Anglai

Morphological investigation into starch bionanocomposites via synchrotron radiation and differential scanning calorimetric

We studied a hydrophilic, plasticized bionanocomposite system involving sorbitol plasticizer, amylose biopolymer, and montmorillonite (MMT) for the presence of competitive interactions among them at different moisture content. Synchrotron analysis via small angle X-ray scattering (SAXS) and thermal analysis using differential scanning calorimetry (DSC) were performed to understand crystalline growth and the distribution of crystalline domains within the samples. The SAXS diffraction patterns showed reduced interhelix spacing in the amylose network indicating strong amylose-sorbitol interactions. Depending on the sorbitol and MMT concentration, these interactions also affected the free moisture content and crystalline domains. Domains of around 95 Å and 312 Å were found in the low-moisture-content samples as compared to a single domain of 95 Å in the high-moisture-content samples. DSC measurements confirmed that the MMT increased the onset and the melting temperature of nanocomposites. Moreover, the results showed that the ternary interactions among sorbitol-amylose-MMT supported the crystalline heterogeneity through secondary nucleation