No. 60 Inhibition Effect of Cyclodextrin on Denaturation of Keratin by Surfactant

Background

Our company has many attract attention technologies in functional food and personal care fields which raises the water solubility, stability and bioavailability of functional ingredients by using the inclusion property of cyclodextrin (CD).

Recently, interaction of CD with protein has been reported. We also reported the stabilization effect of CD for kiwi protein "Actinidin" (* please refer to the newest result of research "43th" of our homepage for details.).

Surfactants were often used in a lot of commodities such as cosmetics, shampoo, toothpaste and detergent. However, surfactants could be causative agents of skin and hair problems.

For example, some of surfactants denature keratin which is main component of hair. Therefore, in this study, stabilization of keratin by the use of CD against denaturation by surfactant was explored.

Experiment

Method

Denaturation of protein was evaluated by analysis of the change of cysteine residue amount on protein surface.

1. Keratin was reacted with sodium dodecyl sulfate as surfactant and CD in water for 12 hr at room temperature.
2. Washing of denaturated keratin by water and phosphate buffer (pH8).
3. Measurement of the absorbance (412nm) of the solution containing keratin reacted with Ellman reagent (DTNB).
   Note : L-cysteine was used for preparation of calibration curve.

Result

Conclusions

CDs could be useful to stabilize proteins against denaturation by surfactants.
This effect could be applied to the developments of new hair- and skin-care products.