Figure 1.

Schematic representation of Nephila clavipes major ampullate spidroin domains (A) and the fiber assembly model in major ampullate spinning duct (B). The colored blocks represent repeat blocks with the color variation indicating the glycine-rich motif and the poly-alanine motif. Along the tapered spinning duct, with the increase of shear force and the decrease of pH, N. clavipes major ampullate spidroins transit from the liquid unfolded state into oligomeric state through the dimerization of N-terminus and the facilitation of C-terminus. The oligomeric state ultimately transitions into a two-phased state, which is comprised of unordered amorphous regions and ordered β-sheet crystalline regions.