The Intermediate Filament Architecture as Determined by X-Ray Diffraction Modeling of Hard Alpha-Keratin

The study used x-ray diffraction modeling to investigate the molecular architecture of hard α-keratin intermediate filaments in human hair. It found that the α-helical coiled coils in the central rod of intermediate filament dimers were straight and likely assembled into tetrameric oligomers, which were irregularly arranged. The radial density across the filament section was uniform, and the architecture was nonordered, differing from other biological fibers. The research highlighted the importance of in vivo studies to understand the natural structure of hard α-keratin IFs and suggested that the formation of IFs is a multistage process influenced by interactions with surrounding tissue components.