| Autor: |
Naito, Akira, Okushita, Keiko, Aoki, Akihiro, Asakura, Tetsuo |
| Zdroj: |
The Journal of Physical Chemistry - Part B; September 2024, Vol. 128 Issue: 35 p8459-8468, 10p |
| Abstrakt: |
The structure of Bombyx morisilk fibroin (SF) is a subject of significant interest due to its remarkable physical properties; however, its atomic-level structure is still not conclusive. We previously proposed a lamellar stacking structure for the crystalline fraction (Cp) with β-turns occurring every eighth amino acid. In this study, we took the following steps: At first, a model of the chain-folded lamellar stacking structure in antipolar and antiparallel β-sheet layers was constructed. Then, dipolar-assisted rotational resonance solid-state NMR spectra were observed to determine the effective internuclear distance (rj,keff) for the uniformly 13C-labeled Cp fraction sample. By comparing the experimentally obtained rj,keff(obs) values with the calculated rj,keff(calc) values from our structural model, a fairly good correlation between the observed and calculated values of the internuclear distances was obtained with a standard deviation of 0.37 Å. This supports the existence of the chain-folded lamellar stacking structure in the SF fiber. These findings contribute to our understanding of the atomic-level structure of SF and its exceptional properties. |
| Databáze: |
Supplemental Index |
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