title: Shear-induced self-assembly of native silk proteins into fibrils studied by atomic force microscopy.
abstract: Noncontact mode atomic force microscopy was used to investigate native silk proteins prepared in different ways. Low protein concentrations revealed that single protein molecules exhibit a simple, round shape with apparent diameters of 20-25 nm. Shearing the native protein solutions after extraction from the gland and prior to drying led to a beads-on-a-string assembly at the nanometer scale. Protein concentration had a significant effect on the morphology of the protein assemblies. At higher protein concentrations, shear-induced alignment into nanofibrils was observed, while lower concentrations lead to the formation of much thinner fibrils with a width of about 8 nm.
authors.affiliation: Department of Zoology, University of Oxford , The Tinbergen Building, Oxford, OX1 3PS, United Kingdom.
authors.forename: Imke
authors.initials: I
authors.lastname: Greving
authors.forename: Minzhen
authors.initials: M
authors.lastname: Cai
authors.forename: Fritz
authors.initials: F
authors.lastname: Vollrath
authors.forename: Hannes C
authors.initials: HC
authors.lastname: Schniepp
mesh_terms: D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D019476:Insect Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D033081:Shear Strength; D047011:Silk / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D013314:Stress, Mechanical
chemical_list: D019476:Insect Proteins; D047011:Silk