Detail publikace

Helical twist direction in the macrofibrils of keratin fibres is left handed

HARLAND, D.P., NOVOTNÁ, V., RICHENA, M., VELAMOOR, S., BOSTINA, M., MCKINNON, A.J.

Originální název

Helical twist direction in the macrofibrils of keratin fibres is left handed

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

angličtina

Originální abstrakt

Macrofibrils, the main structural features within the cortical cells of mammalian hair shafts, are long composite bundles of keratin intermediate filaments (KIFs) embedded in a matrix of keratin-associated proteins. The KIFs can be helically arranged around the macrofibril central axis, making a cylinder within which KIF helical angle relative to macrofibril axis increases approximately linearly from macrofibril centre to edge. Mesophase-based self-assembly has been implicated in the early formation of macrofibrils, which first appear as liquid-crystal tactoids in the bulb of hair follicles. Formation appears to be driven initially by interactions between pre-keratinized KIFs. Differences in the nature of these KIF-KIF interactions could result in all macrofibrils being internally twisted in a single handedness, or a 50:50 mixture of handedness within each cortical cell. We data-mined 41 electron tomograms containing three-dimensional macrofibril data from previously published studies of hair and wool. In all 644 macrofibrils examined we found that within each tomogram all macrofibrils had the same handedness. We concluded that earlier reports of left- and right-handed macrofibrils were due to artefacts of imaging or data processing. A handedness marker was used to confirm (using re-imaged sections from earlier studies) that, in both human and sheep, all macrofibrils are left-handed around the macrofibril axis. We conclude that this state is universal within mammalian hair. This also supports the conclusion that the origin of macrofibril twist is the expression of chiral twisting forces between adjacent KIFs, rather than mesophase splay and bending forces relaxing to twisting forces acting within a confined space.

Klíčová slova

Hair, Wool, Orthocortex, Double-twist, Electron tomography, Data mining, DNA origami

Autoři

HARLAND, D.P., NOVOTNÁ, V., RICHENA, M., VELAMOOR, S., BOSTINA, M., MCKINNON, A.J.

Vydáno

3. 6. 2019

ISSN

1047-8477

Periodikum

JOURNAL OF STRUCTURAL BIOLOGY

Ročník

206

Číslo

3

Stát

Spojené státy americké

Strany od

345

Strany do

348

Strany počet

4

URL

https://www.sciencedirect.com/science/article/pii/S1047847719300735?via%3Dihub

BibTex

@article{BUT157526,
  author="Veronika {Novotná}",
  title="Helical twist direction in the macrofibrils of keratin fibres is left handed",
  journal="JOURNAL OF STRUCTURAL BIOLOGY",
  year="2019",
  volume="206",
  number="3",
  pages="345--348",
  issn="1047-8477",
  url="https://www.sciencedirect.com/science/article/pii/S1047847719300735?via%3Dihub"
}