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Medical contrast media as possible tools for SAXS contrast variation.

ABSTRACT: Small-angle X-ray scattering (SAXS) is increasingly used to extract structural information from a multitude of soft-matter and biological systems in aqueous solution, including polymers, detergents, lipids, colloids, proteins and RNA/DNA. When SAXS data are recorded at multiple contrasts, i.e. at different electron densities of the solvent, the internal electron-density profile of solubilized molecular systems can be probed. However, contrast-variation SAXS has been limited by the range of electron densities available by conventional agents such as sugars, glycerol and salt, and by the fact that many soft-matter and biological systems are modified in their presence. Here we present a pioneering SAXS contrast-variation study on DDM (n-do-decyl-?-d-malto-pyran-oside) micelles by using two highly electron-rich contrast agents from biomedical imaging which belong to the families of gadolinium-based and iodinated molecules. The two agents, Gd-HPDO3A and iohexol, were allowed to attain modifications of the solvent electron density that are 50 to 100% higher than those obtained for sucrose, and are located between the electron densities of proteins and RNA/DNA. In the case of Gd-HPDO3A, an analysis of the internal micellar structure was possible and compared with results obtained with sucrose. In conclusion, medical contrast agents represent a promising class of molecules for SAXS contrast-variation experiments with potential appli-cations for numerous soft-matter and biological systems, including membrane proteins and protein-RNA/DNA complexes.

SUBMITTER: Gabel F

PROVIDER: S-EPMC6608644 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

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Medical contrast media as possible tools for SAXS contrast variation.

Gabel Frank F Engilberge Sylvain S Pérez Javier J Girard Eric E

IUCrJ 20190529 Pt 4

Small-angle X-ray scattering (SAXS) is increasingly used to extract structural information from a multitude of soft-matter and biological systems in aqueous solution, including polymers, detergents, lipids, colloids, proteins and RNA/DNA. When SAXS data are recorded at multiple contrasts, <i>i.e.</i> at different electron densities of the solvent, the internal electron-density profile of solubilized molecular systems can be probed. However, contrast-variation SAXS has been limited by the range o ...[more]

PMID: 31316796

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Medical contrast media as possible tools for SAXS contrast variation.

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Medical contrast media as possible tools for SAXS contrast variation.

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