The conformational analysis of spider dragline silks is difficult because of the amorphous character of the silks. In this article, the fractions of several conformations were determined for three 47-mer peptides, (Glu) 4 (Ala) 6 GlyGly 12 Ala 13 Gly 14 GlnGlyGlyTyrGlyGlyLeuGlySerGlnGly 25 Ala 26 Gly 27 -ArgGlyGlyLeuGlyGlyGln-Gly 35 Ala 36 Gly 37 (Ala) 6 (Glu) 4 , with three underlined 13 C-labeled blocks using a 13 C CP/MAS NMR method. The conformations of the 13 C-labeled sites change significantly depending on the location of the labeled blocks when treated with trifluoroacetic acid, low pH, and freeze-drying. The conformations of Ala 36 and Gly 37 residues are strongly influenced by the specific conformation of the (Ala) 6 sequence at the C-terminal side, but those of other residues, Ala 13 and Gly 14 , and Ala 26 and Gly 27 , are basically not influenced by the conformations of (Ala) 6 . Through hydration of the β-sheet peptide, sharp peaks with random coil could be observed depending on the position of the residue, and this result could be interpreted via the change in the Ramachandran map obtained from the molecular dynamics simulation.

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