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Effect of shampoo, conditioner and permanent waving on the molecular structure of human hair.

Zhang Y, Alsop RJ, Soomro A, Yang FC, Rheinstädter MC - PeerJ (2015)

Bottom Line: We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex.Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments.Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics & Astronomy, McMaster University , Hamilton, ON , Canada.

ABSTRACT
The hair is a filamentous biomaterial consisting of the cuticle, the cortex and the medulla, all held together by the cell membrane complex. The cortex mostly consists of helical keratin proteins that spiral together to form coiled-coil dimers, intermediate filaments, micro-fibrils and macro-fibrils. We used X-ray diffraction to study hair structure on the molecular level, at length scales between ∼3-90 Å, in hopes of developing a diagnostic method for diseases affecting hair structure allowing for fast and noninvasive screening. However, such an approach can only be successful if common hair treatments do not affect molecular hair structure. We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex. Permanent waving treatments are known to break and reform disulfide linkages in the hair. Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments. Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair. Both these observations are related to breaking of the bonds between two coiled-coil keratin dimers.

No MeSH data available.


Calculated diffraction patterns.(A) A hexagonal packing of the coiled-coils well describes the experimental small angle data in Fig. 5B in non-treated hair. (B) The second peak was found to be increased in intensity after perming, consistent with a structure where some coiled-coils are dissolved into monomers and occupy positions in between the dimer locations. [hkl] indices of the primitive and base centred monoclinic lattices used for the calculation are marked. Cartoons show the arrangements of dimers and monomers within the filaments.
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fig-7: Calculated diffraction patterns.(A) A hexagonal packing of the coiled-coils well describes the experimental small angle data in Fig. 5B in non-treated hair. (B) The second peak was found to be increased in intensity after perming, consistent with a structure where some coiled-coils are dissolved into monomers and occupy positions in between the dimer locations. [hkl] indices of the primitive and base centred monoclinic lattices used for the calculation are marked. Cartoons show the arrangements of dimers and monomers within the filaments.

Mentions: The small angle peak pattern in Fig. 5 with peaks at 90 Å, 47 Å and 27 Å is compatible with a 7 dimers arranged on a hexagonal lattice, as shown in Fig. 7A. The structure factor of this structure was calculated and shows excellent agreement with the experimental data. Perming was found to have two effects on the hair structure: (1) a decrease of the coiled-coil signal indicative of a reduced number of protein dimers and (2) an increase of the 47 Å signal. The fact that the small angle peak positions do not change after perming is indicative that the overall structure of the intermediate filaments is not affected by perming. However, decomposition of the keratin coiled-coils may lead to the internal fibre structure shown in Fig. 7B, where individual keratin molecules arrange in a hexagonal pattern.


Effect of shampoo, conditioner and permanent waving on the molecular structure of human hair.

Zhang Y, Alsop RJ, Soomro A, Yang FC, Rheinstädter MC - PeerJ (2015)

Calculated diffraction patterns.(A) A hexagonal packing of the coiled-coils well describes the experimental small angle data in Fig. 5B in non-treated hair. (B) The second peak was found to be increased in intensity after perming, consistent with a structure where some coiled-coils are dissolved into monomers and occupy positions in between the dimer locations. [hkl] indices of the primitive and base centred monoclinic lattices used for the calculation are marked. Cartoons show the arrangements of dimers and monomers within the filaments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4636411&req=5

fig-7: Calculated diffraction patterns.(A) A hexagonal packing of the coiled-coils well describes the experimental small angle data in Fig. 5B in non-treated hair. (B) The second peak was found to be increased in intensity after perming, consistent with a structure where some coiled-coils are dissolved into monomers and occupy positions in between the dimer locations. [hkl] indices of the primitive and base centred monoclinic lattices used for the calculation are marked. Cartoons show the arrangements of dimers and monomers within the filaments.
Mentions: The small angle peak pattern in Fig. 5 with peaks at 90 Å, 47 Å and 27 Å is compatible with a 7 dimers arranged on a hexagonal lattice, as shown in Fig. 7A. The structure factor of this structure was calculated and shows excellent agreement with the experimental data. Perming was found to have two effects on the hair structure: (1) a decrease of the coiled-coil signal indicative of a reduced number of protein dimers and (2) an increase of the 47 Å signal. The fact that the small angle peak positions do not change after perming is indicative that the overall structure of the intermediate filaments is not affected by perming. However, decomposition of the keratin coiled-coils may lead to the internal fibre structure shown in Fig. 7B, where individual keratin molecules arrange in a hexagonal pattern.

Bottom Line: We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex.Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments.Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics & Astronomy, McMaster University , Hamilton, ON , Canada.

ABSTRACT
The hair is a filamentous biomaterial consisting of the cuticle, the cortex and the medulla, all held together by the cell membrane complex. The cortex mostly consists of helical keratin proteins that spiral together to form coiled-coil dimers, intermediate filaments, micro-fibrils and macro-fibrils. We used X-ray diffraction to study hair structure on the molecular level, at length scales between ∼3-90 Å, in hopes of developing a diagnostic method for diseases affecting hair structure allowing for fast and noninvasive screening. However, such an approach can only be successful if common hair treatments do not affect molecular hair structure. We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex. Permanent waving treatments are known to break and reform disulfide linkages in the hair. Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments. Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair. Both these observations are related to breaking of the bonds between two coiled-coil keratin dimers.

No MeSH data available.