Mechanism of Laccase-Assisted Tyrosine Grafting on Keratin Using BSA as a Model Protein

This study explores a gentler alternative to commercial hair perming by using tyrosine as a cross-linking agent in a laccase-assisted reaction. Bovine serum albumin (BSA) was used as a model protein to understand the cross-linking mechanism, revealing the formation of a new cross-linked peptide involving cysteine residues Cys-101 and Cys-176. Molecular dynamics simulations provided insights into protein stability and solvent accessibility. The optimized conditions for curling Asian hair involved pre-treatment with 50.0 mM cysteine followed by 3.0 mM tyrosine grafting. This method showed better initial perming performance compared to commercial products, though with reduced efficiency after washing, but without strength loss and could be easily maintained with a blow-drier. This approach could lead to safer and more user-friendly hair care products.