A schematic diagram of silkworm spinning (IMAGE)
Caption
A schematic diagram of the mechanism by which the silkworm delicately utilizes metal ions and pH gradients to program NSF self-assembly for silk spinning.
NSF is a soluble macromolecular complex and self-assembles into nanofibrils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm in the presence of metal ions. NSFs mainly consist of random coils and are randomly dispersed as isotropic nanofibrils from PSG to ASG-1. With pH decrease from 8.2 (PSG) to 4.8 (ASG), NSF hydrophobicity is gradually enhanced, and NSF concentration increases up to about 30% (w/v). At ASG-2 near the spinneret, NSF nanofibrils self-assemble into herringbone patterns, in which the adjacent nanofibrils are aligned parallel to each other. NSF herringbone patterns flow perpendicular to the spinning duct and are further assembled into anisotropic spinning dopes ready for silkworm spinning.
Credit
©Science China Press
Usage Restrictions
Use with credit.
License
Original content