Visualization of a 21-nm axial periodicity in shadowed keratin filaments and neurofilaments.

Journal Article (Journal Article)

Unidirectional and rotary shadowing techniques have been applied in studying the surface structure of two types of intermediate filaments. Keratin filaments and neurofilaments demonstrate a approximately 21-nm axial periodicity which probably indicates the helical pitch of the outer shell of the filament. Analysis of unidirectionally shadowed keratin showed that the helix is left-handed. The observation of a left-handed helix of 21-nm pitch supports the three-stranded protofilament model of Fraser, Macrae, and Suzuki (1976, J. Mol. Biol. 108:435-452), and indicates that keratin filaments probably consist of 10 three-stranded protofilaments surrounding a core of three such protofilaments, as predicted by models based on x-ray diffraction of hard keratin filaments. Neurofilaments do not demonstrate an easily identifiable hand, so their consistency with the model is, as yet, uncertain.

Full Text

Duke Authors

Cited Authors

  • Milam, L; Erickson, HP

Published Date

  • September 1982

Published In

Volume / Issue

  • 94 / 3

Start / End Page

  • 592 - 596

PubMed ID

  • 6182147

Pubmed Central ID

  • PMC2112206

International Standard Serial Number (ISSN)

  • 0021-9525

Digital Object Identifier (DOI)

  • 10.1083/jcb.94.3.592


  • eng

Conference Location

  • United States