For determination of the conformation of irregular sequences in glycine-rich region of the Nephila clavipes spider dragline silk, the combination of C-13 selectively labeled model peptides for the typical primary structure and their C-13 solid-state NMR observations is very useful (T. Asakura et al. Macromolecules. 51 (2018) 3608-3619). However, spiders produce the fiber through the stretching process in nature and therefore, it is difficult to study conformational change by stretching as mimic using the model peptides because these are generally in the powder form. In this paper, C-13 selectively labeled three model peptides, (Glu)(4)(Ala)(6)GlyGly(12)Ala(13)Gly(14)-GlnGlyGlyTyrGlyGlyLeuGlySerGInGlylaGly(2)-ZArgGly-GlyLeuGlyGlyGInGly(25)Ala(26)Gly(27)(Ala) 6(Glu) 4 with three underlined C-13 labeled blocks and their poly(vinyl alcohol) blend films were prepared and the conformational changes of these peptides were monitored by stretching of the films using C-13 solid-state NMR In addition, the molecular dynamics simulation was done to evaluate change in the conformation of the sequence by stretching theoretically. The fractions of beta-sheet of Ala(36) and Gly(37) residues in glycine-rich region adjacent to the C-terminal (Ala)(6) sequence increased significantly by stretching compared with those of other C-13 labeled Ala and Gly residues. (C) 2019 Published by Elsevier B.V.