The introduction of a mannose residue on carbon 3 of lithocholic acid gives rise to an asymmetric and rigid bolaamphiphilic molecule, which self-assembles in water to form elongated tubular aggregates with an outer diameter of about 20 nm. These tubular structures display a temporal evolution, where the average tube diameter decreases with time, which can be followed by time-resolved small-angle X-ray scattering experiments. Cryogenic transmission electron microscopy images collected as a function of time show that at short times after preparation tubular scrolls are formed via the rolling of layers, after which a complex transformation of the scrolls into single-walled tubules takes place. At long time scales, a further evolution occurs where the tubules both elongate and become narrower. The observed self-assembly confirms the tendency of bile acids and their derivatives to form supramolecular aggregates with an ordered packing of the constituent molecules. It also demonstrates that scrolls can be formed as intermediate structures in the self-assembly process of monodisperse single-walled tubules.
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http://dx.doi.org/10.1021/la500908r | DOI Listing |
Acc Chem Res
August 2024
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060, United States.
ConspectusDuring the last 30 years, theoretical scientists imagined segmental families of monolayer carbon tubules with fullerene-based end-caps. These molecules would possess structural features of both enes (hemispherical end-caps) and tubular belts of single-walled carbon nano (SWCNTs). Yet, their experimental verification remained elusive for decades.
View Article and Find Full Text PDFACS Nano
August 2021
Department of Physics, University of Warwick, Coventry CV4 7AL, U.K.
One-dimensional (1D) atomic chains of CsI were previously reported in double-walled carbon nanotubes with ∼0.8 nm inner diameter. Here, we demonstrate that, while 1D CsI chains form within narrow ∼0.
View Article and Find Full Text PDFNat Commun
January 2018
Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Despite recent advances in the assembly of organic nanotubes, conferral of sequence-defined engineering and dynamic response characteristics to the tubules remains a challenge. Here we report a new family of highly designable and dynamic nanotubes assembled from sequence-defined peptoids through a unique "rolling-up and closure of nanosheet" mechanism. During the assembly process, amorphous spherical particles of amphiphilic peptoid oligomers crystallize to form well-defined nanosheets before folding to form single-walled nanotubes.
View Article and Find Full Text PDFChem Commun (Camb)
November 2016
Wolfson Catalysis Centre, Department of Chemistry University of Oxford, Oxford, OX1 3QR, UK.
Incorporation of CdS quantum dots is shown to significantly promote photocatalytic hydrogen production from water over single-layer MoS in a remote manner via their dispersions on a carbon nanotube as a nanocomposite: the hydrogen evolution rate is found to be critically dependent on the content and structural integrity of the carbon nanotube such that the double-walled carbon nanotube shows superior H production to a single-walled carbon nanotube because the inner carbon tubules survive from the structural damage during functionalization.
View Article and Find Full Text PDFJ Med Genet
December 2014
Department of Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France Inserm, U964, Illkirch, France CNRS, UMR7104, Illkirch, France University of Strasbourg, Illkirch, France Collège de France, Chaire de Génétique Humaine, Illkirch, France.
Background: Tubular aggregate myopathies (TAMs) are muscle disorders characterised by abnormal accumulations of densely packed single-walled or double-walled membrane tubules in muscle fibres. Recently, STIM1, encoding a major calcium sensor of the endoplasmic reticulum, was identified as a TAM gene.
Methods: The present study aims to define the clinical, histological and ultrastructural phenotype of tubular aggregate myopathy and to assess the STIM1 mutation spectrum.
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