Surface modification of wool with protease extracted polypeptides

Polypeptides were extracted from wool protein fibres using the serine type protease Esperase 8.0L (EC 3.4.21.62), a subtilisin from Bacillus sp., in a reducing solution. The extracted polypeptides, in aqueous liquor, were then applied to modify the fibre surface of wool fabric with or without additional protease. The treated wool fabric was subsequently treated with the cross-linking agent, glycerol diglycidyl ether, and then underwent a curing process to affix the polypeptide to the fibre. The resulting knitted fabric showed a very high level of shrink-resistance to machine washing, without excessive fibre damage. Shrinkage of 1–2% could be achieved after 5 times 5A washes with minimal (<1%) weight loss due to washing and a burst strength of 317 kPa.

► Extraction of polypeptides from wool protein fibres using the serine type protease. ► Surface modification of wool with protease extracted polypeptides. ► Fixation of protein polypeptides onto the surface of wool fibres by cross-linking with glycerol diglycidyl ether. ► Development of knitted wool fabrics with high level of shrink-resistance to machine washing, improved whiteness and soft handle.