Hydrolyzed silk (inci)

The silk fibre of insects or spiders consists of the long-chain protein molecules (scleroproteins) fibroin (70-80 %) and the glycoprotein sericin (20-30 %), and is similar in structure to human keratin. Fibroin is a β keratin with a molecular mass of 365,000 kDa. The repeating sequence of amino acids in fibroin is: Gly-Ser-Gly-Ala-Gly-Ala.

Besides the fibre proteins, silk also contains soluble (soluble in propylene glycol or glycerine) glycoproteins such as sericin. The "silk protein" sericin is used in various hair cosmetics and anti-aging products.

1. Kundu B et al (2014) Isolation and processing of silk proteins for biomedical applications. Int J Biol Macromol 70:70-77. https://www.ncbi.nlm.nih.gov/pubmed/24971560