Interaction of polypeptides with hair in different reducing environments

Area of Science:

• Cosmetic Science
• Materials Science
• Biochemistry

Background:

• Hair care innovation requires understanding how cosmetic ingredients interact with hair.
• Damaged hair presents challenges for product performance and consumer satisfaction.

Purpose of the Study:

• To investigate the effect of reducing environments on polypeptide interactions with damaged hair.
• To evaluate the hair-recovering potential of different polypeptides: KP peptide, ELP-KP, BSK recombinant proteins, and hydrolyzed keratin.

Main Methods:

• Hair damage simulation and treatment with various polypeptides.
• Assessment of hair fiber mechanical properties.
• Thermal analysis to study the effect on keratin structure.
• Inclusion of reducing agents like thioglycolic acid and thioanisole.

Main Results:

• KP peptide improved mechanical properties without reducing agents.
• Hydrolyzed keratin and BSK proteins enhanced hair, particularly under reducing conditions.
• ELP-KP showed no significant improvement, likely due to cysteine content and localization.
• Polypeptides increased keratin's alpha-helix denaturation temperature and enthalpy, indicating structural stabilization.

Conclusions:

• Reducing environments significantly influence polypeptide performance in hair repair.
• Polypeptide molecular weight and cysteine content are critical factors for effective hair treatment.
• Specific polypeptides offer distinct benefits for damaged hair recovery based on their properties and application conditions.