2H-Labeling of Silk Fibroin Fibers and Their Structural Characterization by Solid-State 2H NMR
| Autor: | Minoru Osanai, Reiko Shimada, Makoto Demura, Anne S. Ulrich, Mamoru Imanari, Masashi Minami, Tetsuo Asakura, Teruaki Fujito |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Alanine
chemistry.chemical_classification Polymers and Plastics biology Organic Chemistry Fibroin Tricarboxylic acid biology.organism_classification Inorganic Chemistry chemistry.chemical_compound Crystallography SILK chemistry Bombyx mori Polymer chemistry Materials Chemistry Fiber Natural fiber Methyl group |
| Zdroj: | Macromolecules. 30:2429-2435 |
| ISSN: | 1520-5835 0024-9297 |
| Popis: | Three kinds of 2H-labeled Bombyx mori silk fibroin samples (with [2,2-2H2]Gly, [3,3,3-2H3]Ala, or [2,3,5,6-2H4]Tyr) were obtained by oral administration of either the labeled amino acid or 2H2O to 5th instar larvae. The administration of 2H2O alone yielded a high degree of selective deuteration at the alanine methyl group, since the incorporation of 2H2O occurs between fumarate and malate in the tricarboxylic acid (TCA) cycle of the silk fibroin synthetic pathway. Uniaxially oriented silk fibers were prepared as samples for 2H-NMR spectroscopy. An analysis of the quadrupole echo line shape was carried out in order to determine the angle of the deuterium-labeled group relative to the fiber axis, i.e., of the Cα−2H bond vectors in glycine and of Cα−Cβ2H3 in alanine. With the fiber axis aligned parallel to the magnetic field, quadrupole splittings were obtained as 117.8 and 39.8 kHz for [2,2-2H2]Gly- and [3,3,3-2H3]Ala-labeled silk, respectively. These values are identical with those obtained from the 2H-NMR... |
| Databáze: | OpenAIRE |
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