Structural Analysis of Bombyx mori Silk Fibroin Peptides with Formic Acid Treatment Using High-Resolution Solid-State 13C NMR Spectroscopy

Citations Over TimeTop 20% of 2004 papers

Abstract

Bombyx mori silk fibroin fiber is a fibrous protein produced by the silkworm at room temperature and from an aqueous solution whose primary structure is highly repetitive. In this study we analyzed the structural characteristics of native peptides, derived from B. mori silk fibroin, with formic acid treatment using high-resolution solid-state 13C NMR. We establish that the Ser residue bearing a short polar side chain has the ability to stabilize the conformation formed in the model peptides due to its ability to form intermolecular hydrogen bonds involving its hydroxyl group as a donor and the carbonyl groups of other residues as acceptors. On the other hand, insertion of Tyr residue in the basic (AG)n and (AGSGAG)n sequence motifs usually exhibited disruptive effects on the preferred conformations. Moreover, the environmental effect was investigated by mixing the native Cp fraction with the model peptides, showing that there is no significant structural difference on the Ser-containing peptides, while structural transformation was observed on the peptides containing the GAAS unit. This may be attributed to the fact that the Cp fraction promotes the formation of an antiparallel beta-sheet in the Ala-Ala unit. Such periodically disrupted ordered structures in the semicrystalline region of B. mori silk fibroin may be critical not only for facilitating the conformational transformation from silk I to silk II structural form but also for having some correlation with the unique properties of the silk materials.

Related Papers

• → Structure and properties of regenerated Antheraea pernyi silk fibroin in aqueous solution(2006)98 cited
• → An investigation into the effect of potassium ions on the folding of silk fibroin studied by generalized two‐dimensional NMR–NMR correlation and Raman spectroscopy(2007)59 cited
• → Studies on Dynamic Mechanical Properties of Silk Fibroin(1973)7 cited
• → PRESENCE OF α-HELICAL PORTION OF <i>Bombyx mori</i> SILK FIBROIN(1985)2 cited
• Study on the Mechanism of Aggregation of Silk Fibroin in Desalting Process(2003)