Gel formation of solutions of fibrillar proteins during flow in a longitudinal field

The effect of gel formation in the jets of salt-containing solutions of fibrillar proteins (silk fibroin and wool keratin) in a longitudinal hydrodynamic field modeling the process of natural-silk formation in silk glands is studied. Structural transformations in macromolecules are monitored via birefringence measurements, optical rotatory dispersion, and polarization ultramicroscopy. Gel formation under the action of a longitudinal rate gradient is accompanied by the α → β-conformation transition and by the attainment of high degrees of orientation.