JSON
De Oliveira DH, Gowda V, Sparrman T, Gustafsson L, Sanches Pires R, Riekel C, Barth A, Lendel C, Hedhammar M
Nat Commun 15 (1) 4670 [2024-05-31; online 2024-05-31]
The major ampullate Spidroin 1 (MaSp1) is the main protein of the dragline spider silk. The C-terminal (CT) domain of MaSp1 is crucial for the self-assembly into fibers but the details of how it contributes to the fiber formation remain unsolved. Here we exploit the fact that the CT domain can form silk-like fibers by itself to gain knowledge about this transition. Structural investigations of fibers from recombinantly produced CT domain from E. australis MaSp1 reveal an α-helix to β-sheet transition upon fiber formation and highlight the helix No4 segment as most likely to initiate the structural conversion. This prediction is corroborated by the finding that a peptide corresponding to helix No4 has the ability of pH-induced conversion into β-sheets and self-assembly into nanofibrils. Our results provide structural information about the CT domain in fiber form and clues about its role in triggering the structural conversion of spidroins during fiber assembly.
Swedish NMR Centre (SNC) [Collaborative]
PubMed 38821983
DOI 10.1038/s41467-024-49111-5
Crossref 10.1038/s41467-024-49111-5
pmc: PMC11143275
pii: 10.1038/s41467-024-49111-5